[Fix] Scopes constructor handle null parameter

[sarim]

WHY are these changes introduced?

Fixes #290

WHAT is this pull request doing?

Type of change

• Patch: Bug (non-breaking change which fixes an issue)
• Minor: New feature (non-breaking change which adds functionality)
• Major: Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have added a changelog entry, prefixed by the type of change noted above
• I have added/updated tests for this change
• I have updated the documentation for public APIs from the library (if applicable)

[sarim]

I have signed the CLA!

[Suleimanlatrsh]

Thanks for contributing! This package is deprecated and we're archiving this repo, so we're closing all open issues and PRs. Please use shopify-app-php instead, and open new issues there. More context: Rethinking support for PHP/Python packages