base64.h: Fix return type mismatch
base64.h: Fix return type mismatch

Fixes #25220.

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