bug symfony#20833 [HttpKernel] Fix open_basedir compat in DataCollector (nicolas-grekas)

This PR was merged into the 3.2 branch.

Discussion
----------

[HttpKernel] Fix open_basedir compat in DataCollector

| Q             | A
| ------------- | ---
| Branch?       | 3.2
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#20758
| License       | MIT
| Doc PR        | -

Commits
-------

84ad8eb [HttpKernel] Fix open_basedir compat in DataCollector

Author: nicolas-grekas

src/Symfony/Component/HttpKernel/DataCollector/DataCollector.php

@@ -135,7 +135,7 @@ private function decorateVar($var)
                     return self::$stubsCache[$var] = new ClassStub($var);
                 }
             }
-            if (false !== strpos($var, DIRECTORY_SEPARATOR) && false === strpos($var, '://') && false === strpos($var, "\0") && is_file($var)) {
+            if (false !== strpos($var, DIRECTORY_SEPARATOR) && false === strpos($var, '://') && false === strpos($var, "\0") && @is_file($var)) {
                 return self::$stubsCache[$var] = new LinkStub($var);
             }
         }