tests/dns: Add a test for '::1' ipv6 address

Author: 1st1

tests/test_dns.py

@@ -126,6 +126,10 @@ def test_getaddrinfo_18(self):
         self._test_getaddrinfo('localhost', b'http')
         self._test_getaddrinfo('localhost', b'http', type=socket.SOCK_STREAM)
 
+    def test_getaddrinfo_19(self):
+        self._test_getaddrinfo('::1', 80)
+        self._test_getaddrinfo('::1', 80, type=socket.SOCK_STREAM)
+
     ######
 
     def test_getnameinfo_1(self):