What does this MR do?
Adds a prefix to a broken autocomplete URL to get it working again.
After the change by !34295 (merged) the global /autocomplete path no longer works and the /-/ (hyphen) prefix is required to avoid a 404
Fixes #332556 (closed)
Changes made here follows the path strings built for other auto-completes such as in:
Screenshots or Screencasts (strongly suggested)
See #332556 (closed)