Login Auth path invalid

Problem/Motivation

When attempting the authentication workflow providing user credentials. The system redirects the user to a auth end point which appends a language prefix to the auth path. This causes a 404 error and the auth attempt fails.

Steps to reproduce

Try to login with correct credentials.
Testing on a system with a default configuration without internationalization installed this will always fail. As no multilingual settings are provided in this case.
I happen to be working on a multilingual build and even with this enabled the auth path fails as well.

Reviewing the code there is no processing or handling business logic detecting or processing language prefixes in the route file for the module.

Proposed resolution

a) suppress the prefix.

b) extend the classes to detect and process the prefixes and properly pass it along to the end point of the authentication service.

I've attached a patch with suppresses it.