Add Atanner Gaming V6 Server

Auto Updating server to latest bleeding edge build.

servers_v6.json

@@ -8,6 +8,9 @@
   {
     "address": "routerchain.ddns.net"
   },
+  {
+    "address": "mindustry.atannergaming.com:13000"
+  },
   {
     "address": "pandorum.su:8000"
   }