ansible: restrict RPC to localhost by default

scripts/ansible/roles/ava-service/defaults/main.yml

@@ -1 +1,2 @@
+ava_daemon_http_host: localhost
 log_level: info

scripts/ansible/roles/ava-service/templates/ava.service

@@ -14,6 +14,7 @@ RestartSec=1
 User={{ ava_daemon_user }}
 ExecStart={{ bindir }}/ava \
             --public-ip="{{ ansible_facts.default_ipv4.address }}" \
+            --http-host="{{ ava_daemon_http_host }}" \
             --db-dir="{{ ava_daemon_db_dir }}" \
             --plugin-dir="{{ ava_daemon_plugin_dir }}" \
             --log-dir="{{ ava_daemon_log_dir }}" \