Fix uncaught exception in update manager during server version check

What does this MR do and why?

This small fix fixes an error that causes Crafty to crash entirely. When requesting new server jar info, if there is no internet access, the request fails and crashes the program.

How to set up and validate the error locally

1. Run Crafty with a server that is not up to date, but with a server with server update notifications on

2. Crash:

   requests.exceptions.ConnectionError: 
     HTTPSConnectionPool(host='jars.arcadiatech.org', port=443): 
     Max retries exceeded with url: /paper/26.1.2/paper.jar.sha256 
     (Caused by NameResolutionError("HTTPSConnection(host='jars.arcadiatech.org', port=443): 
      Failed to resolve 'jars.arcadiatech.org' ([Errno -3] Temporary failure in name resolution)"))

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• Have you checked this doesn't interfere/conflict/duplicate someone elses work?
• Have you fully tested your changes?
• Have you resolved any lint issues?
• Have you assigned a reviewer?
• Have you applied correct labels?

Fixes: #734 (closed)