Improved performance of love.graphics.present slightly on some platforms

src/modules/window/sdl/Window.cpp

@@ -304,6 +304,7 @@ void Window::setWindowGLAttributes(int fsaa, bool /* sRGB */) const
 	SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
 	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 	SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 1);
+	SDL_GL_SetAttribute(SDL_GL_RETAINED_BACKING, 0);
 
 	// FSAA.
 	SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, (fsaa > 0) ? 1 : 0);