Android client authentication with gitlab

Hi !

Summary

I can't authenticate the Android client on my Mattermost instance with Gitlab authentication.

Steps to reproduce

Install the android client (3.4.1), connect to a mattermost server with only gitlab authentication, click "gitlab" link to authenticate...

The gitlab authentication page is opened in android's browser, not inside the app. So I am authenticated inside the brower, not the app.

Expected behavior

I expect that the authentication form of Gitlab is opened inside mattermost app.

Observed behavior

On desktop browser, it works fine, and there is no popup.

I am using Android 4.4.3.