Don't set OAUTHLIB_INSECURE_TRANSPORT setting in user_data

[nuwang]

This PR:

1. Remove setting OAUTHLIB_INSECURE_TRANSPORT in code. Admins wishing to test insecure localhost redirect endpoints will need to set the environment variable OAUTHLIB_INSECURE_TRANSPORT manually.
2. Removes unnecessary test code
3. Fixes an error when parsing session token

Fixes: #21234 (comment)

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[mvdbeek]

Thank you @nuwang!