Remove deprecated love.window.isCreated alias

--HG--
branch : minor

src/modules/window/wrap_Window.cpp

@@ -561,7 +561,6 @@ static const luaL_Reg functions[] =
 	{ "setFullscreen", w_setFullscreen },
 	{ "getFullscreen", w_getFullscreen },
 	{ "isOpen", w_isOpen },
-	{ "isCreated", w_isOpen }, // For compatibility with old error handlers...
 	{ "close", w_close },
 	{ "getDesktopDimensions", w_getDesktopDimensions },
 	{ "setPosition", w_setPosition },