ci(Jenkinsfile): refs #7643 Tag only master as latest

Jenkinsfile

@@ -72,11 +72,15 @@ pipeline {
                 }
 
                 sh 'docker-compose build --build-arg BUILD_ID=$BUILD_ID --parallel'
-                sh 'docker tag $IMAGE:$TAG $IMAGE:latest'
-
                 sh 'docker login --username $CREDS_USR --password $CREDS_PSW $REGISTRY'
                 sh 'docker push $IMAGE:$TAG'
-                sh 'docker push $IMAGE:latest'
+
+                script {
+                    if (env.BRANCH_NAME == 'master') {
+                        sh 'docker tag $IMAGE:$TAG $IMAGE:latest'
+                        sh 'docker push $IMAGE:latest'
+                    }
+                }
 
                 withKubeConfig([
                     serverUrl: "$KUBERNETES_API",