minor #29013 [HTTP Foundtation] Fix useless space in docblock (ismail…

…1432)

This PR was merged into the 2.8 branch.

Discussion
----------

[HTTP Foundtation] Fix useless space in docblock

I Just removed a useless space in PHP Doc, I don't know if target the 2.8 branch is enough to others SF versions

Commits
-------

6ba7573 fix useless space in docblock

src/Symfony/Component/HttpFoundation/AcceptHeaderItem.php

@@ -65,7 +65,7 @@ public static function fromString($itemValue)
     }
 
     /**
-     * Returns header  value's string representation.
+     * Returns header value's string representation.
      *
      * @return string
      */