Workaround for crash at shutdown in testffmpeg

I'm not sure if this is something in SDL crashing or something in ffmpeg, but it's safer to leave the D3D DLLs loaded.

src/render/direct3d11/SDL_render_d3d11.c

@@ -355,11 +355,11 @@ static void D3D11_ReleaseAll(SDL_Renderer *renderer)
          * to prevent IUnknown::Release() calls from crashing.
          */
         if (data->hD3D11Mod) {
-            SDL_UnloadObject(data->hD3D11Mod);
+            //SDL_UnloadObject(data->hD3D11Mod);
             data->hD3D11Mod = NULL;
         }
         if (data->hDXGIMod) {
-            SDL_UnloadObject(data->hDXGIMod);
+            //SDL_UnloadObject(data->hDXGIMod);
             data->hDXGIMod = NULL;
         }
     }