fixes RequestDataCollector bug, visible when used on Drupal8

In Drupal8 ```$request->attributes->all()``` returns an array with a 0 key whose value is the ```Drupal\user\Entity\User```

```php
array(
 0 => Drupal\user\Entity\User,
 ...
)
```

```('_route' == $key && is_object($value))``` is therefore true which provokes an exception:

```php
FatalErrorException: Error: Call to undefined method Drupal\user\Entity\User::getPath() in [...]/RequestDataCollector.php line 54
```

This patch corrects this with a simple replacement of == by ===

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

@@ -50,9 +50,9 @@ public function collect(Request $request, Response $response, \Exception $except
 
         $attributes = array();
         foreach ($request->attributes->all() as $key => $value) {
-            if ('_route' == $key && is_object($value)) {
+            if ('_route' === $key && is_object($value)) {
                 $attributes['_route'] = $this->varToString($value->getPath());
-            } elseif ('_route_params' == $key) {
+            } elseif ('_route_params' === $key) {
                 foreach ($value as $key => $v) {
                     $attributes['_route_params'][$key] = $this->varToString($v);
                 }