Change default filter when choosing user as Assignee

I have an issue that I want to assign to user. I click the Assignee field and I can start typing and easily find the user I am looking for.
Unfortunatelly it filters the users by username. That is a problem because the users have diacritics in their names e.g.  username: František Řepa.

For example I type in "Repa" and ideally the result should be the username above, but it does not support diacritics so it does not find the desired user.
Is it possible to change filter by login or would it be possible to add support for other languages?