You have to remove from the outfits.xml file man, this file is for ALL players, including GOD.
Players don't have the same issue as Gods do.
Players have a "sex" option, which only allows them to view half of the available outfits, usually.
in data/xml/groups.xml
Each group has "flags" organized to fit their role.
Most Gods have the flag "can_wear_all_outfits" set by default.
If you remove this flag value from your god group, you can disable that option, and your god will only have access to it's gender's outfits.
If you look in your source, const.h, you can find the flag values for your server.
Flag values are created by adding all of the flag values together. 1+2+4+8+16, et cetera.
Find the appropriate flag value for "can_wear_all_outfits", and simply minus that number from your gods flag value, to remove that flag access.