autopoint: disable m4_include and m4_esyscmd when tracing
* autopoint.in (func_trace): Disable m4_include and m4_esyscmd.
* gettextize.in (func_trace): Likewise.
Reported by Bernhard Voelker in
<https://lists.gnu.org/archive/html/bug-gettext/2013-11/msg00011.html>
and suggested by Eric Blake at <https://savannah.gnu.org/bugs/?40083>.
