deployment branches as array v2

.gitlab-ci.yml

@@ -11,7 +11,7 @@ variables:
   MAVEN_OPTS: "-Xmx2048m -Xms2048m"
   SKIP_TESTS: "true"
 
-  DEPLOYMENT_BRANCHES: ["master", "rc3.0", "rc3.1"]
+  DEPLOYMENT_BRANCHES: {"master", "rc3.0", "rc3.1"}
 
   DOCKER_CLI: "docker run --rm -v /var/run/docker.sock:/var/run/docker.sock -v $CI_PROJECT_DIR/maven_repo:/root/.m2 -w /usr/src/mymaven -v $CI_PROJECT_DIR:/usr/src/mymaven --env-file .env.list $MAVEN_IMAGE"
   MELODIC_UPPERWARE_CLI: "mvn --batch-mode -N -Dmaven.test.skip=$SKIP_TESTS -f pom.xml"