ElasticSearch shall bind to 127.0.0.1

Steps to reproduce:
1. Reboot your host
2. Start Opencast
3. Have a look at what ports are listened (use netstat -tulpen | grep java on Linux, use lsof -i -P | grep java on MacOS)

Actual Results:
Sometimes (at first startup), TCP 9200 and TCP 9300 listen to 0.0.0.0 (any).

Expected Results:
TCP 9200 and TCP 9300 shall only listen to 127.0.0.1

Workaround (if any):