Issue update branch selection disable

[ejouvin]

• Gitea version (or commit ref): 1.11.4
• Git version:
• Operating system:
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No
  • Not relevant
• Log gist:

Description

Why on an existing issue, the branch dropdown box is disabled ?
We can affect branch during creation, but not during update.
...

Screenshots

[jolheiser]

Duplicate of #3620