Fixed "Repair All" bug in LilVendor.lua

Fixed a bug where an error would show ingame saying the referenced window was nil. Changed Line 936-937 to the right reference. 
You can reproduce this error if you log into the game and directly try to repair all your gear with the "Repair All" button on the repair tab. (the following error will show)
http://i.imgur.com/35QidLD.png