Fix the `String::get_base_dir()` logic to properly check for top level directories on Windows.
Fix the `String::get_base_dir()` logic to properly check for top level directories on Windows.

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