Listen on IPv4 only by default.

Listening on the empty address allows connections on both ipv4 and ipv6 and  AdminWebServer gets confused about the IP change caused by i.e. nginx.

Author: veluca93

config/cms.conf.sample

@@ -140,7 +140,7 @@
     "_help": "Listening HTTP address and port for the AWS. If you access",
     "_help": "it through a proxy running on the same host you could put",
     "_help": "127.0.0.1 here for additional security.",
-    "admin_listen_address": "",
+    "admin_listen_address": "0.0.0.0",
     "admin_listen_port":    8889,
 
     "_help": "Login cookie duration for admins in seconds.",