Tweak dupsigs test output

Use a different visual separator, since "====", "----" and "____" is
used by pytest to separate the log output.

Author: nicki-krizek

bin/tests/system/dupsigs/tests.sh

@@ -38,7 +38,7 @@ end=$((start + 140))
 
 while [ $now -lt $end ]; do
         et=$((now - start))
-	echo "=============== $et ============"
+	echo "............... $et ............"
 	$JOURNALPRINT ns1/signing.test.db.signed.jnl | $PERL check_journal.pl
 	$DIG axfr signing.test -p ${PORT} @10.53.0.1 > dig.out.at$et
 	awk '$4 == "RRSIG" { print $11 }' dig.out.at$et | sort | uniq -c