tests: older_soa: longer interval to ensure the test won't fail

tests-extra/tests/zone/older_soa/data/example.zone

 $ORIGIN example.
 $TTL 1200
 
-@ SOA ns admin 20110102 5 5 13 600
+@ SOA ns admin 20110102 7 7 16 600
 ns AAAA ::0
 added A 1.2.3.4

tests-extra/tests/zone/older_soa/test.py

@@ -5,15 +5,15 @@
 from dnstest.test import Test
 
 EXPIRE_SLEEP = 13
-RESYNC_SLEEP = 5
-TEST_START_EXPECTED = 3
+RESYNC_SLEEP = 7
+TEST_START_EXPECTED = 4
 
 t = Test()
 
 master = t.server("knot")
 slave = t.server("knot")
 
-# this zone has refresh = 5s, retry = 5s and expire = 13s
+# this zone has refresh = 7s, retry = 7s and expire = 16s
 zone = t.zone("example.", storage=".")
 t.link(zone, master, slave)