Fixes crash when clearing guides in empty scene
Fixes crash when clearing guides in empty scene

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