Update wlif_utils.h

This will raise the limit from 2 to 5 possible Bridges with WLAN and WPA. 

Default:
2 bridges with WLAN WPA are supported. 
The third bridge will not support security, like WPA, on the associated WLAN.

Fixed already Tomato:
http://repo.or.cz/w/tomato.git/commit/d1b97fef19bec4e5714b0c01f2cc748dfa788e00