avoid DNS of local names in fast tests (small optimization)

fail2ban/tests/utils.py

@@ -308,6 +308,9 @@ def F2B_SkipIfNoNetwork():
 	c.set('2001:db8::ffff', 'test-other')
 	c.set('87.142.124.10', 'test-host')
 	if unittest.F2B.no_network: # pragma: no cover
+		if unittest.F2B.fast: # pragma: no cover
+			for i in ('127.0.0.1', '::1'): # DNSUtils.dnsToIp('localhost')
+				c.set(i, 'localhost')
 		# precache all ip to dns used in test cases:
 		c.set('192.0.2.888', None)
 		c.set('8.8.4.4', 'dns.google')
@@ -329,8 +332,9 @@ def F2B_SkipIfNoNetwork():
 			c.set(*i)
 		# if fast - precache all host names as localhost addresses (speed-up getSelfIPs/ignoreself):
 		if unittest.F2B.fast: # pragma: no cover
+			ips = set([IPAddr('127.0.0.1'), IPAddr('::1')]); # DNSUtils.dnsToIp('localhost')
 			for i in DNSUtils.getSelfNames():
-				c.set(i, DNSUtils.dnsToIp('localhost'))
+				c.set(i, ips)
 
 
 def mtimesleep():