Fix branch name created from issue with non-latin title

What does this MR do?

Fix empty branch name created from issue with non-latin title

Screenshots

Taken from issue with title Правки

Before

After

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/30767 https://gitlab.com/gitlab-org/gitlab-ce/issues/39293 https://gitlab.com/gitlab-org/gitlab-ce/issues/1