Correctly invoke rabbit_log:log/4 here

Author: michaelklishin

src/rabbit_reader.erl

@@ -409,7 +409,7 @@ log_connection_exception(Severity, Name, {heartbeat_timeout, TimeoutSec}) ->
 log_connection_exception(Severity, Name, {connection_closed_abruptly,
                                           #v1{connection = #connection{user  = #user{username = Username},
                                                                        vhost = VHost}}}) ->
-    rabbit_log:log(Severity, "closing AMQP connection ~p (~s, vhost: '~s', user: '~s'):~nclient unexpectedly closed TCP connection~n",
+    rabbit_log:log(rabbit_log_connection, Severity, "closing AMQP connection ~p (~s, vhost: '~s', user: '~s'):~nclient unexpectedly closed TCP connection~n",
         [self(), Name, VHost, Username]);
 %% when client abruptly closes connection before connection.open/authentication/authorization
 %% succeeded, don't log username and vhost as 'none'