fix ENET_SOCKOPT_NONBLOCK when value is 0
fix ENET_SOCKOPT_NONBLOCK when value is 0

shumtn/enet,eisenhauer/enet,alexxvk/enet,alexxvk/enet,michalslonina/enet,elliotwhisper/enet,lsalzman/enet,elliotwhisper/enet,nicolaichuk/enet,kitech/enet,nicolaichuk/enet,michalslonina/enet,stiljg/enet,shumtn/enet,chenbk85/enet,stiljg/enet,wangscript/enet,freeminer/enet,eisenhauer/enet,eisenhauer/enet,chenbk85/enet,kitech/enet,freeminer/enet,wangscript/enet