Fix auto-enable of _input processing when _input() method is set.
Fix auto-enable of _input processing when _input() method is set.

Since f3f4a11c processing of callbacks such as `_process`, `_fixed_process`, etc will be
automatically enabled when the corresponding method is found in the script.
However, for _input() this wasn't working.
That's simply because `_input` wasn't initialized in `SceneStringNames` ^^

exabon/godot,MarianoGnu/godot,pkowal1982/godot,ZuBsPaCe/godot,mcanders/godot,Max-Might/godot,pkowal1982/godot,vkbsb/godot,tomreyn/godot,NateWardawg/godot,Zylann/godot,tomreyn/godot,tomreyn/godot,n-pigeon/godot,RebelliousX/Go_Dot,firefly2442/godot,ageazrael/godot,Valentactive/godot,RandomShaper/godot,ficoos/godot,josempans/godot,zicklag/godot,RebelliousX/Go_Dot,honix/godot,Faless/godot,morrow1nd/godot,vnen/godot,ageazrael/godot,okamstudio/godot,Marqin/godot,pkowal1982/godot,Marqin/godot,MarianoGnu/godot,NateWardawg/godot,BastiaanOlij/godot,Max-Might/godot,vkbsb/godot,okamstudio/godot,RandomShaper/godot,MarianoGnu/godot,MrMaidx/godot,ZuBsPaCe/godot,sanikoyes/godot,mcanders/godot,DmitriySalnikov/godot,firefly2442/godot,sanikoyes/godot,RandomShaper/godot,Valentactive/godot,vnen/godot,Brickcaster/godot,honix/godot,jejung/godot,vnen/godot,Paulloz/godot,sanikoyes/godot,n-pigeon/godot,guilhermefelipecgs/godot,ZuBsPaCe/godot,Marqin/godot,vkbsb/godot,vkbsb/godot,ZuBsPaCe/godot,NateWardawg/godot,vnen/godot,DmitriySalnikov/godot,pkowal1982/godot,Paulloz/godot,MarianoGnu/godot,Shockblast/godot,Shockblast/godot,firefly2442/godot,ex/godot,NateWardawg/godot,ageazrael/godot,godotengine/godot,DmitriySalnikov/godot,godotengine/godot,morrow1nd/godot,jejung/godot,Valentactive/godot,firefly2442/godot,ageazrael/godot,FateAce/godot,Faless/godot,Faless/godot,Valentactive/godot,mcanders/godot,tomreyn/godot,Brickcaster/godot,groud/godot,Paulloz/godot,zicklag/godot,josempans/godot,FateAce/godot,vnen/godot,vkbsb/godot,pkowal1982/godot,Valentactive/godot,DmitriySalnikov/godot,vkbsb/godot,godotengine/godot,DmitriySalnikov/godot,MrMaidx/godot,exabon/godot,groud/godot,n-pigeon/godot,MrMaidx/godot,Max-Might/godot,okamstudio/godot,morrow1nd/godot,firefly2442/godot,guilhermefelipecgs/godot,guilhermefelipecgs/godot,RandomShaper/godot,mcanders/godot,jejung/godot,firefly2442/godot,morrow1nd/godot,DmitriySalnikov/godot,godotengine/godot,ex/godot,okamstudio/godot,vnen/godot,Faless/godot,Marqin/godot,RandomShaper/godot,Shockblast/godot,n-pigeon/godot,Zylann/godot,n-pigeon/godot,jejung/godot,honix/godot,NateWardawg/godot,DmitriySalnikov/godot,Shockblast/godot,Paulloz/godot,MrMaidx/godot,ex/godot,akien-mga/godot,RandomShaper/godot,Shockblast/godot,Valentactive/godot,okamstudio/godot,RandomShaper/godot,josempans/godot,Marqin/godot,RebelliousX/Go_Dot,josempans/godot,morrow1nd/godot,ageazrael/godot,BastiaanOlij/godot,zicklag/godot,Brickcaster/godot,Faless/godot,ZuBsPaCe/godot,groud/godot,Zylann/godot,Brickcaster/godot,akien-mga/godot,MarianoGnu/godot,Zylann/godot,Max-Might/godot,akien-mga/godot,Valentactive/godot,Shockblast/godot,ficoos/godot,ageazrael/godot,BastiaanOlij/godot,NateWardawg/godot,okamstudio/godot,ex/godot,exabon/godot,Brickcaster/godot,ZuBsPaCe/godot,Valentactive/godot,jejung/godot,godotengine/godot,Shockblast/godot,akien-mga/godot,okamstudio/godot,groud/godot,Faless/godot,zicklag/godot,MrMaidx/godot,guilhermefelipecgs/godot,vkbsb/godot,guilhermefelipecgs/godot,akien-mga/godot,okamstudio/godot,ex/godot,Faless/godot,NateWardawg/godot,ageazrael/godot,firefly2442/godot,jejung/godot,sanikoyes/godot,RebelliousX/Go_Dot,vkbsb/godot,honix/godot,Brickcaster/godot,MarianoGnu/godot,Paulloz/godot,Brickcaster/godot,zicklag/godot,firefly2442/godot,sanikoyes/godot,Paulloz/godot,ex/godot,ficoos/godot,FateAce/godot,groud/godot,n-pigeon/godot,NateWardawg/godot,MrMaidx/godot,josempans/godot,BastiaanOlij/godot,guilhermefelipecgs/godot,josempans/godot,NateWardawg/godot,sanikoyes/godot,vnen/godot,sanikoyes/godot,pkowal1982/godot,ficoos/godot,RebelliousX/Go_Dot,okamstudio/godot,zicklag/godot,akien-mga/godot,BastiaanOlij/godot,honix/godot,FateAce/godot,Zylann/godot,ficoos/godot,guilhermefelipecgs/godot,ex/godot,akien-mga/godot,ZuBsPaCe/godot,godotengine/godot,MarianoGnu/godot,mcanders/godot,mcanders/godot,MarianoGnu/godot,Paulloz/godot,Shockblast/godot,BastiaanOlij/godot,BastiaanOlij/godot,Faless/godot,Max-Might/godot,FateAce/godot,n-pigeon/godot,exabon/godot,vnen/godot,Marqin/godot,FateAce/godot,Zylann/godot,akien-mga/godot,RebelliousX/Go_Dot,Max-Might/godot,godotengine/godot,josempans/godot,pkowal1982/godot,BastiaanOlij/godot,Zylann/godot,pkowal1982/godot,ficoos/godot,godotengine/godot,Zylann/godot,groud/godot,honix/godot,ex/godot,tomreyn/godot,okamstudio/godot,exabon/godot,ZuBsPaCe/godot,exabon/godot,morrow1nd/godot,guilhermefelipecgs/godot,josempans/godot,sanikoyes/godot