fix smoke-test-plugins-ssl to work when ::1 does not resolve at all.

My previous change only fixed it when it resolves to something different than localhost.
But in some cases, it does not resolve at all, we must specify the IP.

Original commit: elastic/x-pack-elasticsearch@547eb4c42f

elasticsearch/qa/smoke-test-plugins-ssl/build.gradle

@@ -20,11 +20,17 @@ task createKey(type: LoggedExec) {
   }
   String subjectAlternateNames = 'san=dns:localhost,ip:127.0.0.1'
   // some machines have a different name for ipv6 loopback,
-  // at least on ubuntu its ip6-localhost
+  // at least on ubuntu its ip6-localhost. other machines, like windows,
+  // won't resolve it back to any hostname at all. Try to setup ipv6 to
+  // work in all cases.
   try {
       String localhost6 = InetAddress.getByName("::1").getCanonicalHostName()
       if (!localhost6.equals("localhost")) {
-          subjectAlternateNames += ",dns:" + localhost6
+          if (localhost6.startsWith("0")) {
+              subjectAlternateNames += ",ip:" + localhost6
+          } else {
+              subjectAlternateNames += ",dns:" + localhost6
+          }
       }
   } catch (UnknownHostException ok) {
       // e.g. no ipv6 support