Using env OAUTH_URI variable instead of const

[dakswagup]

Requirements

• [X] I have added test coverage for new or changed functionality
• [X] I have followed the repository's pull request submission guidelines
• [X] I have validated my changes against all supported platform versions

Describe the solution you've provided

The bridge is not reading from the env variable causing issues with sandboxes or scratch orgs to login.

[hroederld]

Hello @dakswagup

Thank you for the fix!