Add debug logging for endpoint_url in AWS Connection

[vmtuan12]

Add debug logging when endpoint_url is missing in extra config of AWS Connection. This helps user identify the problem easier, as described in #52697

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[boring-cyborg]

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[potiuk]

redis is flaky and we want to fix it soon

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.