gtk-play example assumes that GTK's GL support always works if it is
compiled in and first tries to use gtkglsink element which leads to
problems if there are errors while instantiating GL context at a much
later stage. This failure isn't detected and there is no fallback at
this point.
gtkglsink works on wayland though using poky defaults with gtk+3 since
the gdk backend does support egl with wayland but it doesn't with x11.
Disable the gtk plugin to ensure gtk-play just moves on when gtkglsink
isn't present. This was the default when gtk was part of -plugins-bad
before upgrade to 1.14.0.
Fixes [YOCTO #12832]
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
