minor #16749 [Messenger] Fix typo in amqp option name user -> login (Kozzi11)

This PR was merged into the 5.4 branch.

Discussion
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[Messenger] Fix typo in amqp option name user -> login

This will fix #15566

Commits
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89ecc0a [Messenger] Fix typo in option name user->login

Author: javiereguiluz

messenger.rst

@@ -1239,6 +1239,7 @@ The transport has a number of options:
                                               calls.
 ``host``                                      Hostname of the AMQP service
 ``key``                                       Path to the client key in PEM format.
+``login``                                     Username to use to connect the AMQP service
 ``password``                                  Password to use to connect to the AMQP service
 ``persistent``                                                                                   ``'false'``
 ``port``                                      Port of the AMQP service
@@ -1247,7 +1248,6 @@ The transport has a number of options:
                                               greater seconds. May be fractional.
 ``retry``
 ``sasl_method``
-``user``                                      Username to use to connect the AMQP service
 ``verify``                                    Enable or disable peer verification. If peer
                                               verification is enabled then the common name in
                                               the server certificate must match the server