add rollback to gitea jenkinsfile

dockerfiles/services/gitea/Jenkinsfile

@@ -47,6 +47,16 @@ pipeline {
                     sh "curl -If http://dkhost:10080"
                 }
             }
+            post {
+                failure {
+                    dir(WORKDIR) {
+                        sh """
+                            export DOCKER_HOST=${DOCKER_HOST}
+                            docker service rollback gitea
+                        """
+                    }
+                }
+            }
         }
 
     }