A user can already join the server with the same name as an already joined user

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Describe the bug
n+1 users of the same name can join the server at any time

To Reproduce
Steps to reproduce the behavior:

1. Start a Server
2. Start 2 instances of Crash
3. Join both with the name "Example"
4. Try creating geometry on one crash instance

Expected behavior
Server should refuse entry

Version Info (please complete the following information):

• Rhino Version [7/8.x.x]
• Crash Version [1.4.x]

Additional context
The server etc does seem to work nicely, but it's weird.