Fix or obviate need for and work around failed CKEditor Mentions update hook

The 2.x branch of CKEditor Mentions introduces an update hook 8002 which is causing an error when we update to it.

Update aborted by: ckeditor_mentions_update_8002

In this commit for issue Use the official CKEditor mention plugin [#3009308] |

It could be a flaw in the update hook itself (why return false and so abort?) or it may be, as often happens, an update hook that only makes sense within the context of the 2.x branch and the module would work fine with an uninstall and reinstall (which would run the install hook and not the update hooks).

Second run of updates resulted in this notice:

[warning] Schema information for module ckeditor_mentions_realname was missing from the database. You should manually review the module updates and your database to check if any updates have been skipped up to, and including, ckeditor_mentions_realname_update_8000().

but this time the updates completed.