perf: Skip registering auth delegate if it's already registered

[mtrezza]

New Pull Request Checklist

• [x] I am not disclosing a vulnerability.
• [x] I am creating this PR in reference to an issue.

Issue Description

When registering the same auth delegate again, it is actually fully re-registered in the SDK.

Closes: #n/a

Approach

Don't register same auth delegate again if its already registered. Instead just do nothing.

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[parseplatformorg]

🎉 This change has been released in version 2.1.1