Fixed a bug in extension update check test

[veler]

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• New feature or enhancement
• UI change (please include screenshot!)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
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What is the current behavior?

Nuget API requires the package name to be in lowercase. The URL we were generating didn't have the package name in lowercase.

What is the new behavior?

It is not in lowercase.

Other information

Quality check

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