message: fix i18n for UserMenu spinner
diff: "Switch theme": "Switch theme",
  "User menu": "User menu",
  "Community and user menu": "Community and user menu",
  - "Currently joining %(count)s rooms|one": "Currently joining %(count)s room",
  "Currently joining %(count)s rooms|other": "Currently joining %(count)s rooms",
  + "Currently joining %(count)s rooms|one": "Currently joining %(count)s room",
  "Could not load user profile": "Could not load user profile",
  "Decrypted event source": "Decrypted event source",
  "Original event source": "Original event source",
  