Remove misleading nonexistant flag hint

[evrimoztamur]

./mach build -d does not report any errors.
./mach test-tidy --faster does not report any errors.
The change fixes #11197.

The change does not require tests because it is a small change that doesn't change any core functionality.

---

This change is

[highfive]

Thanks for the pull request, and welcome! The Servo team is excited to review your changes, and you should hear from @Ms2ger (or someone else) soon.

[Ms2ger]

@bors-servo r+

[bors-servo]

📌 Commit b9d3310 has been approved by Ms2ger

[bors-servo]

⌛ Testing commit b9d3310 with merge 8274f7e...

[bors-servo]

💔 Test failed - mac-rel-wpt

[highfive]

  ▶ TIMEOUT [expected OK] /cors/redirect-origin.htm
  │ 
  │ thread 'http_loader for http://www1.web-platform.test:8000/cors/resources/cors-makeheader.py?origin=*&location=http%3A%2F%2Fwww1.web-platform.test%3A8000%2Fcors%2Fresources%2Fcors-makeheader.py%3Forigin%3Dhttp%3A%2F%2Fwww1.web-platform.test%3A8000%26get_value%3Dlast%2640_1&40_0' panicked at 'could not initialize thread_rng: Too many open files (os error 24)', ../src/libstd/rand/mod.rs:159
  │ stack backtrace:
  │ thread 'http_loader for http://www1.web-platform.test:8000/cors/resources/cors-makeheader.py?origin=*&location=http%3A%2F%2Fwww2.web-platform.test%3A8000%2Fcors%2Fresources%2Fcors-makeheader.py%3Forigin%3Dhttp%3A%2F%2Fwww1.web-platform.test%3A8000%26get_value%3Dlast%2641_1&41_0' panicked at 'could not initialize thread_rng: Too many open files (os error 24)', ../src/libstd/rand/mod.rs:159
  │    1:        0x1091df128 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
  │    2:        0x1091e55b5 - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
  │    3:        0x1091e51ce - std::panicking::default_hook::hc2c969e7453d080c
  │    4:        0x108974272 - util::panicking::initiate_panic_hook::_$u7b$$u7b$closure$u7d$$u7d$::_$u7b$$u7b$closure$u7d$$u7d$::ha2bd86c312dc8d7a
  │    5:        0x1091ccd82 - std::panicking::rust_panic_with_hook::hfe203e3083c2b544
  │    6:        0x1091e5b76 - std::panicking::begin_panic::h4889569716505182
  │    7:        0x1091ce678 - std::panicking::begin_panic_fmt::h484cd47786497f03
  │    8:        0x1091e5fe9 - std::rand::thread_rng::THREAD_RNG_KEY::__init::h536e3917997a1628
  │ thread 'http_loader for http://www1.web-platform.test:8000/cors/resources/cors-makeheader.py?origin=null&location=http%3A%2F%2Fwww2.web-platform.test%3A8000%2Fcors%2Fresources%2Fcors-makeheader.py%3Forigin%3D*%26get_value%3Dlast%2638_1&38_0' panicked at 'could not initialize thread_rng: Too many open files (os error 24)', /Users/servo/.cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.3.14/src/lib.rs:873
  │    9:        0x1091cd38c - std::rand::thread_rng::h789d00d1fce4f79b
  │   10:        0x107972dac - _<collections..hash..map..RandomState as core..default..Default>::default::ha847494db5044892
  │   11:        0x1079b1b00 - net::http_loader::load::h981055a57a1b11f1
  │   12:        0x1079ad7a2 - std::panicking::try::call::h7738ffab0c454f42
  │   13:        0x1091e8d3b - __rust_try
  │   14:        0x1091e8cd5 - __rust_maybe_catch_panic
  │   15:        0x1079afd24 - _<F as std..boxed..FnBox<A>>::call_box::hfad4324b0bbd8499
  │   16:        0x1</span><span class="stdout">091e45d8 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  │   17:     0x7fff8c3c2059 - _pthread_body
  │   18:     0x7fff8c3c1fd6 - _pthread_start
  │ stack backtrace:
  │    1:        0x1091df128 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
  │    2:        0x1091e55b5 - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
  │    3:        0x1091e51ce - std::panicking::default_hook::hc2c969e7453d080c
  │    4:        0x108974272 - util::panicking::initiate_panic_hook::_$u7b$$u7b$closure$u7d$$u7d$::_$u7b$$u7b$closure$u7d$$u7d$::ha2bd86c312dc8d7a
  │    5:        0x1091ccd82 - std::panicking::rust_panic_with_hook::hfe203e3083c2b544
  │    6:        0x1091e5b76 - std::panicking::begin_panic::h4889569716505182
  │    7:        0x1091ce678 - std::panicking::begin_panic_fmt::h484cd47786497f03
  │    8:        0x1091e5fe9 - std::rand::thread_rng::THREAD_RNG_KEY::__init::h536e3917997a1628
  │    9:        0x1091cd38c - std::rand::thread_rng::h789d00d1fce4f79b
  │   10:        0x107972dac - _&lt;collections..hash..map..RandomState as core..default..Default&gt;::default::ha847494db5044892
  │   11:        0x1079b1b00 - net::http_loader::load::h981055a57a1b11f1
  │   12:        0x1079ad7a2 - std::panicking::try::call::h7738ffab0c454f42
  │   13:        0x1091e8d3b - __rust_try
  │   14:        0x1091e8cd5 - __rust_maybe_catch_panic
  │   15:        0x1079afd24 - _&lt;F as std..boxed..FnBox&lt;A&gt;&gt;::call_box::hfad4324b0bbd8499
  │   16:        0x1091e45d8 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  │   17:     0x7fff8c3c2059 - _pthread_body
  │   18:     0x7fff8c3c1fd6 - _pthread_start
  │ stack backtrace:
  │    1:        0x1091df128 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
  │    2:        0x1091e55b5 - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
  │    3:        0x1091e51ce - std::panicking::default_hook::hc2c969e7453d080c
  │    4:        0x108974272 - util::panicking::initiate_panic_hook::_$u7b$$u7b$closure$u7d$$u7d$::_$u7b$$u7b$closure$u7d$$u7d$::ha2bd86c312dc8d7a
  │    5:        0x1091ccd82 - std::panicking::rust_panic_with_hook::hfe203e3083c2b544
  │    6:        0x1091e5b76 - std::panicking::begin_panic::h4889569716505182
  │    7:        0x1091ce678 - std::panicking::begin_panic_fmt::h484cd47786497f03
  │    8:        0x1091b703f - rand::thread_rng::THREAD_RNG_KEY::__init::h4e1387a2e4a21393
  │    9:        0x1091b6e7c - rand::thread_rng::he394b446ab605489
  │   10:        0x108bc0562 - uuid::Uuid::new_v4::hc206acac9c7e580d
  │   11:        0x1079b27cb - net::http_loader::load::h981055a57a1b11f1
  │   12:        0x1079ad7a2 - std::panicking::try::call::h7738ffab0c454f42
  │   13:        0x1091e8d3b - __rust_try
  │   14:        0x1091e8cd5 - __rust_maybe_catch_panic
  │   15:        0x1079afd24 - _&lt;F as std..boxed..FnBox&lt;A&gt;&gt;::call_box::hfad4324b0bbd8499
  │   16:        0x1091e45d8 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  │   17:     0x7fff8c3c2059 - _pthread_body
  └   18:     0x7fff8c3c1fd6 - _pthread_start

  ▶ Unexpected subtest result in /cors/redirect-origin.htm:
  │ TIMEOUT [expected FAIL] remote (null) to remote2 (*), expect to fail
  └   → Test timed out

  ▶ Unexpected subtest result in /cors/redirect-origin.htm:
  │ TIMEOUT [expected PASS] remote (*) to remote (http://www1.web-platform.test:8000), expect to fail
  └   → Test timed out

  ▶ Unexpected subtest result in /cors/redirect-origin.htm:
  │ TIMEOUT [expected PASS] remote (*) to remote2 (http://www1.web-platform.test:8000), expect to fail
  └   → Test timed out

[Ms2ger]

@bors-servo r+

• #11100

[bors-servo]

💡 This pull request was already approved, no need to approve it again.

• This pull request previously failed. You should add more commits to fix the bug, or use retry to trigger a build again.
• There's another pull request that is currently being tested, blocking this pull request: #11263

[bors-servo]

📌 Commit b9d3310 has been approved by Ms2ger

[Ms2ger]

@bors-servo retry

[bors-servo]

⌛ Testing commit b9d3310 with merge be9dfb2...

[bors-servo]

☀️ Test successful - android, arm32, arm64, linux-dev, linux-rel, mac-dev-unit, mac-rel-css, mac-rel-wpt, windows