patch-grecs_tests_epp.at

--- grecs/tests/epp.at.orig	2021-09-06 16:30:24 UTC
+++ grecs/tests/epp.at
@@ -15,7 +15,9 @@
 # along with Grecs.  If not, see <http://www.gnu.org/licenses/>.
 AT_SETUP([External preprocessor])
 
-AT_CHECK([m4 -s </dev/null 2>/dev/null || AT_SKIP_TEST])
+AT_CHECK([m4 -s </dev/null 2>/dev/null || AT_SKIP_TEST],[0],[stdout])
+# On FreeBSD, m4 outputs a single '#line 1 "stdin"' line
+AT_CHECK([s=`sed -e '/^#line/d' stdout`; test -z "$s" || AT_SKIP_TEST])
 
 AT_CHECK([
 AT_DATA([input],