[clangd] Fix a lit-test.

Summary:
Fixes https://bugs.llvm.org/show_bug.cgi?id=40593.
Non-percent-encoded chars doesn't cause any problems on the input-side since we
assume everything after authority section is data and don't interpret them as
delimeters.

Reviewers: sammccall

Subscribers: ilya-biryukov, ioeric, MaskRay, jkorous, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58126

llvm-svn: 353857

clang-tools-extra/test/clangd/Inputs/background-index/definition.jsonrpc

@@ -44,7 +44,7 @@
     }
   }
 }
-# CHECK: "uri": "file://DIRECTORY/foo.cpp"
+# CHECK: "uri": "file://{{.*}}/foo.cpp"
 ---
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
 ---