adds zlib dependency for all platforms
adds zlib dependency for all platforms

mottx/lwip,neophob/lwip,lpicanco/lwip,weareu/lwip,cocos-creator/lwip,EyalAr/lwip,EyalAr/lwip,gimox/lwip,MAMISHO/lwip,cocos-creator/lwip,michaelBenin/lwip,EyalAr/lwip,GrimDerp/lwip,antoinepairet/lwip,neophob/lwip,domosapien/lwip,neophob/lwip,sanemat/lwip,domosapien/lwip,oliversalzburg/lwip,unbornchikken/lwip,GrimDerp/lwip,fireball-x/lwip,gimox/lwip,lpicanco/lwip,MAMISHO/lwip,domosapien/lwip,antoinepairet/lwip,sanemat/lwip,gimox/lwip,fireball-x/lwip,oliversalzburg/lwip,lpicanco/lwip,cocos-creator/lwip,lpicanco/lwip,GrimDerp/lwip,cocos-creator/lwip,unbornchikken/lwip,GrimDerp/lwip,oliversalzburg/lwip,MAMISHO/lwip,domosapien/lwip,unbornchikken/lwip,neophob/lwip,unbornchikken/lwip,fireball-x/lwip,gimox/lwip,fireball-x/lwip,EyalAr/lwip,MAMISHO/lwip,antoinepairet/lwip,oliversalzburg/lwip,weareu/lwip,michaelBenin/lwip,sanemat/lwip,michaelBenin/lwip,antoinepairet/lwip,michaelBenin/lwip,mottx/lwip,weareu/lwip,sanemat/lwip,weareu/lwip,mottx/lwip,mottx/lwip