Fix crash on GDNative API json generator exit.
Fix crash on GDNative API json generator exit.

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