Note that there is one issue with this fix. The newly created issue
uses a text input box for the multiselect.

If you usually use a option multiselect (e.g. with select2 to provide
a better multiselect interface) it will be overridden in the default
interface. The normal (list) javascript assistant works ok.

This is probably a feature enhancement that should be in a different
issue, but I thought I'd mention it here since it's a side effect
of the fix.