Fix z_index applied twice for TileMap layers
Fix z_index applied twice for TileMap layers

Shockblast/godot,vnen/godot,pkowal1982/godot,josempans/godot,guilhermefelipecgs/godot,vnen/godot,godotengine/godot,pkowal1982/godot,BastiaanOlij/godot,Valentactive/godot,Zylann/godot,akien-mga/godot,vnen/godot,josempans/godot,Shockblast/godot,vnen/godot,akien-mga/godot,vnen/godot,Zylann/godot,akien-mga/godot,Shockblast/godot,ZuBsPaCe/godot,firefly2442/godot,DmitriySalnikov/godot,Valentactive/godot,josempans/godot,guilhermefelipecgs/godot,vkbsb/godot,Faless/godot,BastiaanOlij/godot,Faless/godot,sanikoyes/godot,DmitriySalnikov/godot,Shockblast/godot,DmitriySalnikov/godot,sanikoyes/godot,akien-mga/godot,DmitriySalnikov/godot,DmitriySalnikov/godot,sanikoyes/godot,pkowal1982/godot,guilhermefelipecgs/godot,vnen/godot,DmitriySalnikov/godot,ZuBsPaCe/godot,ZuBsPaCe/godot,vkbsb/godot,vkbsb/godot,josempans/godot,Shockblast/godot,Zylann/godot,ZuBsPaCe/godot,Valentactive/godot,ZuBsPaCe/godot,pkowal1982/godot,Valentactive/godot,Faless/godot,DmitriySalnikov/godot,Faless/godot,sanikoyes/godot,vkbsb/godot,firefly2442/godot,Valentactive/godot,firefly2442/godot,guilhermefelipecgs/godot,godotengine/godot,akien-mga/godot,BastiaanOlij/godot,Valentactive/godot,guilhermefelipecgs/godot,Zylann/godot,BastiaanOlij/godot,Zylann/godot,guilhermefelipecgs/godot,pkowal1982/godot,Zylann/godot,pkowal1982/godot,Zylann/godot,vkbsb/godot,Shockblast/godot,Valentactive/godot,godotengine/godot,pkowal1982/godot,akien-mga/godot,ZuBsPaCe/godot,vkbsb/godot,sanikoyes/godot,godotengine/godot,ZuBsPaCe/godot,Faless/godot,godotengine/godot,vkbsb/godot,godotengine/godot,ZuBsPaCe/godot,Shockblast/godot,BastiaanOlij/godot,akien-mga/godot,BastiaanOlij/godot,firefly2442/godot,godotengine/godot,firefly2442/godot,vnen/godot,Valentactive/godot,sanikoyes/godot,josempans/godot,josempans/godot,akien-mga/godot,firefly2442/godot,BastiaanOlij/godot,guilhermefelipecgs/godot,Faless/godot,Shockblast/godot,josempans/godot,firefly2442/godot,BastiaanOlij/godot,Faless/godot,guilhermefelipecgs/godot,Zylann/godot,josempans/godot,vnen/godot,sanikoyes/godot,Faless/godot,firefly2442/godot,vkbsb/godot,sanikoyes/godot,godotengine/godot,pkowal1982/godot