minor #18340 [WebProfilerBundle] Add missing use statement. (camporter)

This PR was merged into the 2.7 branch.

Discussion
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[WebProfilerBundle] Add missing use statement.

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

The RouterController creates a Request in getTraces, but does not have a `use` statement, which causes an exception when trying to view profile routing in >2.7.

Commits
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0d31c3e [WebProfilerBundle] Add missing use statement.

Author: xabbuh

src/Symfony/Bundle/WebProfilerBundle/Controller/RouterController.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Bundle\WebProfilerBundle\Controller;
 
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Matcher\UrlMatcherInterface;
 use Symfony\Component\Routing\Matcher\TraceableUrlMatcher;