Merge branch 'build-notification-null' into 'master'

Adds a null check to build notifications

Closes #27948

See merge request !9108

app/assets/javascripts/merge_request_widget.js.es6

@@ -154,7 +154,7 @@ require('./smart_interval');
       return $.getJSON(this.opts.ci_status_url, (function(_this) {
         return function(data) {
           var message, status, title;
-          if (data.status === '') {
+          if (!data.status) {
             return;
           }
           if (data.environments && data.environments.length) _this.renderEnvironments(data.environments);