refactor: simplify clientlogin logic

- Removed the unnecessary try/catch block around the get_token call. The
  code would already have thrown an exception earlier if the site was
  uninitialized, making this block redundant.
- Eliminated the while True loop, as every branch of the loop had a
  return statement, preventing it from executing more than once.
- Replaced outdated printf-style string formatting with str.format().
- Renamed the `login` variable to `response`