Merge branch '6.3' into 6.4

* 6.3:
  Fix the installation instructions of symfony/psr-http-message-bridge

Author: javiereguiluz

components/psr7.rst

@@ -10,7 +10,7 @@ Installation
 
 .. code-block:: terminal
 
-    $ composer require symfony/psr-http-message-bridge
+    $ composer require symfony/psr-http-message-bridge:^2.3
 
 .. include:: /components/require_autoload.rst.inc