dont run secondary nameserver checks if the zone's nameservers aren't correct...

dont run secondary nameserver checks if the zone's nameservers aren't correct to begin with, possibly because the user is using external DNS, see #582

management/status_checks.py

@@ -395,6 +395,8 @@ def check_dns_zone(domain, env, output, dns_zonefiles):
 	correct_ns = "; ".join(sorted(["ns1." + env['PRIMARY_HOSTNAME']] + secondary_ns))
 	ip = query_dns(domain, "A")
 
+	probably_external_dns = False
+
 	if existing_ns.lower() == correct_ns.lower():
 		output.print_ok("Nameservers are set correctly at registrar. [%s]" % correct_ns)
 	elif ip == correct_ip:
@@ -402,6 +404,7 @@ def check_dns_zone(domain, env, output, dns_zonefiles):
 		output.print_warning("""The nameservers set on this domain at your domain name registrar should be %s. They are currently %s.
 			If you are using External DNS, this may be OK."""
 				% (correct_ns, existing_ns) )
+		probably_external_dns = True
 	else:
 		output.print_error("""The nameservers set on this domain are incorrect. They are currently %s. Use your domain name registrar's
 			control panel to set the nameservers to %s."""
@@ -409,7 +412,7 @@ def check_dns_zone(domain, env, output, dns_zonefiles):
 
 	# Check that each custom secondary nameserver resolves the IP address.
 	
-	if custom_secondary_ns:
+	if custom_secondary_ns and not probably_external_dns:
 		for ns in custom_secondary_ns:
 			# We must first resolve the nameserver to an IP address so we can query it.
 			ns_ip = query_dns(ns, "A")