fix: server exception loop

[slb1988]

When NetworkManager.SceneManager.SynchronizeNetworkObjects got exception, there will always got exception in AddClient for add ConnectedClients dictionary multi times. Client and Server all get stuck.

Changelog

• Added: The package whose Changelog should be added to should be in the header. Delete the changelog section entirely if it's not needed.
• Fixed: If you update multiple packages, create a new section with a new header for the other package.
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Testing and Documentation

• No tests have been added.
• Includes unit tests.
• Includes integration tests.
• No documentation changes or additions were necessary.
• Includes documentation for previously-undocumented public API entry points.
• Includes edits to existing public API documentation.

[unity-cla-assistant]

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[NoelStephensUnity]

Interesting... I think I see what you are talking about with that change.
Will look at it closer tomorrow....but thank you very much for the PR submission and contributing to help make NGO better!
👍 💯