vo_opengl: move X11 backends before Wayland

Wayland is still too amateurish, and multiple features don't work,
including critical ones. There is no solution in sight, so prefer X11.
(Which seems to mostly work ok via xwayland.)

Once all problems are solved, the defaults can be switched back.

video/out/opengl/context.c

@@ -65,9 +65,6 @@ static const struct mpgl_driver *const backends[] = {
 #if HAVE_GL_DXINTEROP
     &mpgl_driver_dxinterop,
 #endif
-#if HAVE_GL_WAYLAND
-    &mpgl_driver_wayland,
-#endif
 #if HAVE_GL_X11
     &mpgl_driver_x11_probe,
 #endif
@@ -77,6 +74,9 @@ static const struct mpgl_driver *const backends[] = {
 #if HAVE_GL_X11
     &mpgl_driver_x11,
 #endif
+#if HAVE_GL_WAYLAND
+    &mpgl_driver_wayland,
+#endif
 #if HAVE_EGL_DRM
     &mpgl_driver_drm,
     &mpgl_driver_drm_egl,