Multiple 'Loading' messages in dropdown menu

Summary

Screenshot_20160930_094909

Steps to reproduce

I found it on GitLab.com
it is reproducible if a server responds not much quickly.

  1. Open any issue.
  2. Type @ in a textarea. You will see a dropdown menu with one Loading message.
  3. Just wait about 10 seconds. You will see three Loading messages.

Expected behavior

There should be only one Loading message.

Actual behavior

Three Loading messages after about 10 second of waiting.

Output of checks

Results of GitLab environment info

GitLab Enterprise Edition 8.12.3-ee 54ec1a6e