While testing MDLQA-8327, it was observed that search feature in community block is broken.

This has been introduced after MDL-51536 got integrated last week. (Search works by reverting to commit before it and fails on 668980be3e2cf4da61e28a8bc3e33c8dcc94cd35)

Steps to reproduce:

1. Register (public instance) moodle to http://hub.moodle.org
2. Login as a teacher (with the capability block/community:add allowed), turn editing on in the course and add a community block.
3. Follow the search link in the community block.
4. Search for a community course
5. You will observe an error

   An error occurred when retrieving the course listing from the selected hub, please try again later. (Unknown error)