Fix engine always trying to load OU.BIN instead of OU.DAT in case it doesn't exist

[frabert]

I have always been experiencing this on my desktop but not on my laptop, for some reason Utils::getCaseSensitivePath returns a valid path even for nonexistant files, so the engine would always try to load OU.BIN instead of OU.DAT on desktop, making the game crash every time I start a dialog with an NPC

[ataulien]

Would you add the check to Utils::getCaseSensitivePath, too?

[frabert]

You mean checking for file existance inside of getCaseSensitivePath?

[ataulien]

That function should probably return something like an empty string for files that don't exist.

[frabert]

Done, turns out the function was trying to be smart on Windows by exploiting the fact that the filesystem is case-insensitive to begin with, there