(Update) use peer id for client blacklist instead of user agent

[Roardom]

Maybe should just check both and add an extra column in the db.

[what-the-diff]

PR Summary

• Optimized checkClient function
  The checkClient function now uses a more efficient loop (foreach) instead of the older in_array method, improving performance.
• Introduction of peerId variable
  A new variable, called $peerId, is created to store the peer id from the request query string.
• Enhanced client validation
  The PR enhances the client validation process by checking for any part of the peer id matching with a blacklisted client. If a match is found, a TrackerException 128 (client blacklisted) is thrown.