Merge branch '7.1' into 7.2

* 7.1:
  Add missing argument
  [Mesenger] Mention that some option doesn't have docs

Author: javiereguiluz

messenger.rst

@@ -1522,7 +1522,7 @@ The transport has a number of options:
     (no description available)
 
 ``sasl_method``
-
+    (no description available)
 
 ``connection_name``
     For custom connection names (requires at least version 1.10 of the PHP AMQP

serializer.rst

@@ -1803,7 +1803,7 @@ property. This can be used instead of
             },
         ],
     ];
-    $jsonContent = $serializer->serialize($person, 'json');
+    $jsonContent = $serializer->serialize($person, 'json', $context);
     // $jsonContent contains {"name":"cordoval","age":34,"createdAt":"2014-03-22T09:43:12-0500"}
 
 Advanced Deserialization