Set title to value instead of return of backend.setTitle

[joshtynjala]

@superpowers04 Is __backend.setTitle(value) returning the wrong value?

[superpowers04]

Oh god, I am dumb. I uhh thought __backend was a reference to a native library, completely forgetting that the compiler would throw a fit if the function returned something other than a String and completely ignoring that WindowBackend is a typedef at the bottom of the file to a normal Haxe class. I apologise