add when branch master clause on build stage

Jenkinsfile

@@ -216,6 +216,9 @@ pipeline {
                 script {
                     jsonConfig.gCube_release.Components.each { group_name, component_list ->
                         stage("build ${group_name} components") {
+                        	when {
+                        	    branch "master"
+                        	}
                             buildComponents items: component_list?.collect { "${it.name}" },
                                     "${maven_settings_file}", "${maven_activation_property}", "${maven_local_repo_path}", jobs
                             echo "Done with ${group_name} components"