refactor(gitlab): don’t warn for status transition errors

lib/platform/gitlab/index.js

@@ -383,8 +383,17 @@ async function setBranchStatus(
   try {
     await get.post(url, { body: options });
   } catch (err) /* istanbul ignore next */ {
-    logger.debug({ err });
-    logger.warn('Failed to set branch status');
+    if (
+      err.message &&
+      err.messages.startsWith(
+        'Cannot transition status via :enqueue from :pending'
+      )
+    ) {
+      logger.info('Ignoring status transition error');
+    } else {
+      logger.debug({ err });
+      logger.warn('Failed to set branch status');
+    }
   }
 }