Move miniz submodule url to JonnyH's github
Move miniz submodule url to JonnyH's github

The one we previously used appears to have disappeared

FranciscoDA/OpenApoc,pmprog/OpenApoc,ShadowDancer/OpenApoc,steveschnepp/OpenApoc,ShadowDancer/OpenApoc,FranciscoDA/OpenApoc,FranciscoDA/OpenApoc,steveschnepp/OpenApoc,pmprog/OpenApoc,Istrebitel/OpenApoc,Istrebitel/OpenApoc