remi-realtime-db v0.2.2

Open port

When add new rdb server, please add and open its port.

Given the port need to open is 8090, the command is:

firewall-cmd --zone=public --add-port=8090/tcp --permanent
firewall-cmd --reload

ref: https://www.digitalocean.com/community/tutorials/opening-a-port-on-linux