VE-1199: Adjust focus mode for User namespace

https://wikia-inc.atlassian.net/browse/VE-1199 @mklucsarits 
This does not seem like a proper way of using mw.config (mw.Map). Take a look here: https://www.mediawiki.org/wiki/RL/DM#mediaWiki.config.
Also I suggest putting some inline comment around "2" - NS_USER (or whatever it is).