fixed clang build (nullptr vs 0 in C-SPI)

src/mirrage/graphic/src/settings.cpp

@@ -8,7 +8,7 @@ namespace mirrage::graphic {
 	auto default_window_settings(int display) -> Window_settings
 	{
 #ifdef NDEBUG
-		auto mode = SDL_DisplayMode{SDL_PIXELFORMAT_UNKNOWN, 0, 0, 0, 0};
+		auto mode = SDL_DisplayMode{SDL_PIXELFORMAT_UNKNOWN, 0, 0, 0, nullptr};
 		if(SDL_GetDisplayMode(display, 0, &mode) == 0) {
 			return Window_settings{mode.w, mode.h, display, Fullscreen::yes};
 		}