Revert "[HTML5] Better engine config parsing."
Revert "[HTML5] Better engine config parsing."

This reverts commit 2f509f1b12c33234a0d8f0e254c727fd92e57720.

Breaks closure compiler builds.
And adds a warning for future readers.

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