ares_parse_a_reply: fix CNAME response parsing

Reply to a CNAME query doesn't contain addresses, causing
ares_parse_a_reply() to bail out with ARES_ENODATA

Bug: http://groups.google.com/group/nodejs/browse_thread/thread/a1268c9ea5e9ad9b

ares_parse_a_reply.c

@@ -201,7 +201,9 @@ int ares_parse_a_reply(const unsigned char *abuf, int alen,
         }
     }
 
-  if (status == ARES_SUCCESS && naddrs == 0)
+  if (status == ARES_SUCCESS && naddrs == 0 && naliases == 0)
+    /* the check for naliases to be zero is to make sure CNAME responses
+       don't get caught here */
     status = ARES_ENODATA;
   if (status == ARES_SUCCESS)
     {