Remove `:latest` from mqtt image tag

5 jobs for integrate-MQTT in 26 minutes and 9 seconds (queued for 39 seconds)
Status Name Job ID Coverage
  Windows
passed masterJobWindows #485961
Windows10

00:10:17

 
  Linux Compile
passed CompileJobLinux #485962

00:05:11

87.0%
 
  Integration
passed MqttIntegrationJob #485963

00:02:58

passed Ros2IntegrationJob #485965

00:05:01

passed RosIntegrationJob #485964

00:10:40