makerst: Fix duplicate `.xml` extension in some error messages
makerst: Fix duplicate `.xml` extension in some error messages

Previously, a file name could appear as e.g. `ProjectSettings.xml.xml`
when one of the 3 modified errors was reported.

Zylann/godot,ZuBsPaCe/godot,BastiaanOlij/godot,godotengine/godot,godotengine/godot,akien-mga/godot,sanikoyes/godot,ZuBsPaCe/godot,Valentactive/godot,akien-mga/godot,Shockblast/godot,BastiaanOlij/godot,firefly2442/godot,godotengine/godot,pkowal1982/godot,Shockblast/godot,josempans/godot,pkowal1982/godot,sanikoyes/godot,ZuBsPaCe/godot,firefly2442/godot,vkbsb/godot,Valentactive/godot,godotengine/godot,firefly2442/godot,guilhermefelipecgs/godot,godotengine/godot,akien-mga/godot,sanikoyes/godot,guilhermefelipecgs/godot,josempans/godot,Shockblast/godot,Zylann/godot,Shockblast/godot,vkbsb/godot,Valentactive/godot,guilhermefelipecgs/godot,guilhermefelipecgs/godot,vkbsb/godot,vkbsb/godot,pkowal1982/godot,josempans/godot,BastiaanOlij/godot,akien-mga/godot,BastiaanOlij/godot,pkowal1982/godot,vkbsb/godot,Shockblast/godot,firefly2442/godot,ZuBsPaCe/godot,akien-mga/godot,ZuBsPaCe/godot,guilhermefelipecgs/godot,Valentactive/godot,josempans/godot,Valentactive/godot,akien-mga/godot,godotengine/godot,godotengine/godot,Zylann/godot,pkowal1982/godot,ZuBsPaCe/godot,BastiaanOlij/godot,Shockblast/godot,vkbsb/godot,akien-mga/godot,ZuBsPaCe/godot,pkowal1982/godot,josempans/godot,firefly2442/godot,sanikoyes/godot,josempans/godot,vkbsb/godot,josempans/godot,Valentactive/godot,Zylann/godot,josempans/godot,sanikoyes/godot,Zylann/godot,sanikoyes/godot,sanikoyes/godot,BastiaanOlij/godot,Valentactive/godot,BastiaanOlij/godot,Zylann/godot,Shockblast/godot,guilhermefelipecgs/godot,pkowal1982/godot,akien-mga/godot,pkowal1982/godot,Valentactive/godot,firefly2442/godot,Shockblast/godot,firefly2442/godot,godotengine/godot,ZuBsPaCe/godot,BastiaanOlij/godot,firefly2442/godot,Zylann/godot,vkbsb/godot,guilhermefelipecgs/godot,Zylann/godot,guilhermefelipecgs/godot,sanikoyes/godot