Fix Gnome (/Xorg) 3.24/3.26 stutter on NVIDIA

..By recompiling mutter without threaded GL sync.
From the source tree:

1. cd mutter-3.26.1/
2. cp src/backends/x11/meta-renderer-x11.c src/backends/x11/meta-renderer-x11.c.orig
3. sed 's/cogl_xlib_renderer_set_threaded_swap_wait_enabled (cogl_renderer, TRUE/cogl_xlib_renderer_set_threaded_swap_wait_enabled (cogl_renderer, FALSE/' -i src/backends/x11/meta-renderer-x11.c

Now compile, install and restart it..

The problem arise from a timing issue.