remove unused definition from makefile
remove unused definition from makefile

lwahlmeier/avian,joshuawarner32/avian,bgould/avian,minor-jason/avian,bigfatbrowncat/avian-pack.avian,ucdseniordesign/avian,lwahlmeier/avian,joshuawarner32/avian,marcinolawski/avian,bgould/avian,ucdseniordesign/avian,dicej/avian,dicej/avian,MaartenR/avian,bgould/avian,bgould/avian,MaartenR/avian,marcinolawski/avian,MaartenR/avian,dicej/avian,lwahlmeier/avian,getlantern/avian,bigfatbrowncat/avian-pack.avian,getlantern/avian,joshuawarner32/avian,bigfatbrowncat/avian-pack.avian,badlogic/avian,minor-jason/avian,minor-jason/avian,marcinolawski/avian,badlogic/avian,lostdj/avian,getlantern/avian,lostdj/avian,ucdseniordesign/avian,badlogic/avian,marcinolawski/avian,joshuawarner32/avian,getlantern/avian,ucdseniordesign/avian,badlogic/avian,dicej/avian,lwahlmeier/avian,bigfatbrowncat/avian-pack.avian,minor-jason/avian,MaartenR/avian,lostdj/avian,lostdj/avian