Trim spaces from after the realm

[spaetow]

A little enhancement for the username validation would be to ensure that there are no spaces after the realm part of the username since we all know that spaces are a no no in the realm part. It should be part of sanity checking, purely because we know that different OSes may auto-complete something and insert a space after the auto-completed term. It helps avoid the inevitable "I typed my username correctly, promise!" plea from the user when in fact they did, but the phone OS decided that a space after the auto-complete was a given.