Check a nil URL to fix crashes connecting to socket

[HeyImChris]

Please select one of the following

• I am removing an existing difference between facebook/react-native and microsoft/react-native-macos 👍
• I am cherry-picking a change from Facebook's react-native into microsoft/react-native-macos 👍
• I am making a fix / change for the macOS implementation of react-native
• I am making a change required for Microsoft usage of react-native

Summary

We're seeing crashes because a nil URL is passed in here. We're investigating the root cause of who is passing in nil, but we can also be better at graciously handling an invalid URL. Instead of crashing, let's assert and skip the websocket connection.

After this goes into master I can cherry-pick into our stable branches.

Changelog

[Apple] [Bug] - Nil check nil websocket URL

Test Plan

I can't repro this failure myself, but we've gotten reports of it. A simple nil check and assert should at least prevent crashes. I did the basic due diligence of verifying with the API that it requires a non-null parameter and will throw an exception if we pass in nil.

[pull-bot]

Messages

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