FR OATH module doesn't work if user has a space in the username

Steps to reproduce:

• Create an end-user with a space in the username
• try to register your device with that user

Having a username with space in it can be quite common when using AD as user store. Potentially there are problems with other special characters as well.

Looks like the Android application (at least) is unable to deal with QR codes that have spaces in them and it will show the error message of "The token specified was invalid!"