fix(oxauth): introspection endpoint returns error for valid basic client authentication and invalid token

[yuriyz]

Describe the issue

Introspection endpoint returns error for valid basic client authentication and invalid token.

{ "error_description": "The resource owner or authorization server denied the request.", "error": "access_denied" }

Expected behavior

It should return 200 {"active": false}

Actual behavior

{ "error_description": "The resource owner or authorization server denied the request.", "error": "access_denied" }

Support: 11855