libgimp: disable tile command range check in plug-in tile backend
In gimp_tile_backend_plugin_command(), disable the range check for
the input tile command. This check prevents us from adding new
tile commands to GEGL without breaking the ABI; yet, the next GEGL
release will add a new command. We're going to have to decide what
to do about this, but for now, let's just disable the check, so
that at least GIMP 2.10.6 is compatible with newer versions of
GEGL, no matter how we end up handling this.
(cherry picked from commit
90ed3c8d3ab7fd9e3ea05d0b0e9522dda4036876)