Provider config in Site Administration page breaks UI

[adelowo]

• Gitea version (or commit ref): 81059a2
• Git version: Not relevant
• Operating system: MacOS
• 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:

Kindly take a look at the screenshot, it is scrollable all the way to the right