d/t/upstream: skip func_regexp_pcre on s390x

New tests were added along work for but those are still failing on
s390x. To pass dep8, but not skip on unittests entirely this disables
the particular test on s390x.

[1]: https://jira.mariadb.org/browse/MDEV-13412



Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

debian/tests/upstream

@@ -27,6 +27,11 @@ main.ctype_uca : Requires writable /usr
 rpl.rpl_gtid_mode : Requires starting server as root ref http://bugs.mysql.com/bug.php?id=70517
 EOF
 
+ARCH=$(dpkg --print-architecture)
+if [ "$ARCH" = "s390x" ]; then
+    echo "main.func_regexp_pcre : recursion fails on s390x https://bugs.launchpad.net/ubuntu/+source/mariadb-10.1/+bug/1723947" >> $SKIP_TEST_LST
+fi
+
 cd /usr/share/mysql/mysql-test
 echo "starting mysql-test-tun.pl..."
 perl -I. ./mysql-test-run.pl --suite=main --vardir=$WORKDIR/var --tmpdir=$WORKDIR/tmp \