Merge pull request #1686 from rabbitmq/lrb-set_parameter-docs

Change example to use parameter that exists

Author: michaelklishin

docs/rabbitmqctl.8

@@ -978,13 +978,13 @@ In most shells you are very likely to need to quote this.
 .El
 .Pp
 For example, this command sets the parameter
-.Qq local_username
+.Qq node01
 for the
-.Qq federation
-component in the default virtual host to the JSON term
+.Qq federation-upstream
+component in the default virtual host to the following JSON
 .Qq guest :
 .sp
-.Dl rabbitmqctl set_parameter federation local_username Qq guest
+.Dl rabbitmqctl set_parameter federation-upstream node01 '{"uri":"amqp://user:password@server/%2F","ack-mode":"on-publish"}'
 .\" ------------------------------------
 .It Cm clear_parameter Oo Fl p Ar vhost Oc Ar component_name Ar key
 Clears a parameter.
@@ -996,12 +996,12 @@ The name of the parameter being cleared.
 .El
 .Pp
 For example, this command clears the parameter
-.Qq local_username
+.Qq node01
 for the
-.Qq federation
+.Qq federation-upstream
 component in the default virtual host:
 .sp
-.Dl rabbitmqctl clear_parameter federation local_username
+.Dl rabbitmqctl clear_parameter federation-upstream node01
 .\" ------------------------------------
 .It Cm list_parameters Op Fl p Ar vhost
 Lists all parameters for a virtual host.