Skip setting SDL_HINT_VIDEO_X11_FORCE_EGL on NixOS

see 60fae35

src/BizHawk.Bizware.Graphics/OpenGL/SDL2OpenGLContext.cs

@@ -1,5 +1,7 @@
 // #define DEBUG_OPENGL
 
+using System.IO;
+
 #if DEBUG_OPENGL
 using System.Runtime.InteropServices;
 using Silk.NET.OpenGL;
@@ -29,7 +31,7 @@ static SDL2OpenGLContext()
 				// try to use EGL if it is available
 				// GLX is the old API, and is the more or less "deprecated" at this point, and potentially more buggy with some drivers
 				// we do need to a bit more work, in case EGL is not actually available or potentially doesn't have desktop GL support
-				SDL_SetHint(SDL_HINT_VIDEO_X11_FORCE_EGL, "1");
+				if (!Directory.Exists("/nix")/* this is just for me --yoshi */) SDL_SetHint(SDL_HINT_VIDEO_X11_FORCE_EGL, "1");
 			}
 
 			// init SDL video