We usually forcibly delete any gettext macros we come across to ensure that the
latest versions we ship are used, but if we're building gettext then it's a bad
idea to delete the gettext macros.
Historically this hasn't been a problem as the top-level gettext configure
doesn't use AM_GNU_GETTEXT so the deletion was never done, but this may change.
Signed-off-by: Ross Burton <ross.burton@intel.com>
