Merge branch '7.3' into 7.4

* 7.3:
  Fix confusing wording about redeliver_timeout duration

Author: javiereguiluz

messenger.rst

@@ -1733,7 +1733,7 @@ The transport has a number of options:
 
     .. note::
 
-        Set ``redeliver_timeout`` to a greater value than your slowest message
+        Set ``redeliver_timeout`` to a greater value than your longest message
         duration. Otherwise, some messages will start a second time while the
         first one is still being handled.