tests-extra: extend xfr limits in Bind configuration

tests-extra/tools/dnstest/server.py

@@ -661,6 +661,10 @@ class Bind(Server):
         s.item("auth-nxdomain", "no")
         s.item("recursion", "no")
         s.item("masterfile-format", "text")
+        s.item("max-refresh-time", "2")
+        s.item("max-retry-time", "2")
+        s.item("transfers-in", "30")
+        s.item("transfers-out", "30")
         s.end()
 
         s.begin("key", self.ctlkey.name)