[TT-10544] - Fix panics while no license is provided

[buraksekili]

Description

When no license is provided, jwt token becomes a nil pointer which causes a panic while checking if jwt is valid or not.

Related Issue

https://tyktech.atlassian.net/browse/TT-10544

Motivation and Context

Test Coverage For This Change

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

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