opengl: remove duplicated texture format

src/render/opengl/SDL_render_gl.c

@@ -1678,7 +1678,6 @@ static int GL_CreateRenderer(SDL_Renderer *renderer, SDL_Window *window, SDL_Pro
 
     renderer->info.name = GL_RenderDriver.name;
     SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_ARGB8888);
-    SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_ARGB8888);
     SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_ABGR8888);
     SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_XRGB8888);
     SDL_AddSupportedTextureFormat(renderer, SDL_PIXELFORMAT_XBGR8888);