minor #39293 [HttpFoundation] Ignore stack trace printed by Xdebug 3 …

…(derrabus)

This PR was merged into the 4.4 branch.

Discussion
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[HttpFoundation] Ignore stack trace printed by Xdebug 3

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | N/A
| License       | MIT
| Doc PR        | N/A

If we're running HttpFoundation's functional tests with Xdebug 3, a stack trace will be printed when a warning is emitted. This confuses our `cookie_max_age` test currently where we perform a `setcookie()` call that will emit a warning.

I have patched the corresponding fixture so the printed stack trace is ignored.

A failed test can be seen here: https://travis-ci.com/github/symfony/symfony/jobs/452077515#L11078

Commits
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b67baa4 [HttpFoundation] Ignore stack trace printed by Xdebug 3.

src/Symfony/Component/HttpFoundation/Tests/Fixtures/response-functional/cookie_max_age.expected

@@ -1,6 +1,6 @@
 
 Warning: Expiry date cannot have a year greater than 9999 in %scookie_max_age.php on line 10
-
+%a
 Array
 (
     [0] => Content-Type: text/plain; charset=utf-8