ovn-ic: systemd service does not use ovn_ctl_opts

The ovn-ic.service script doesn't use OVN_CTL_OPTS from environment file.

This way, we won't be able to start the daemon automatically by loading configurations via file, just like ovn-ic-db service already does.

The idea to solve the problem would be to add the EnvironmentFile=-/etc/default/ovn-ic to the ovn-ic.service and add the opts when starting the daemon via ovn-ctl.

e.g.: /etc/default/ovn-ic file

OVN_CTL_OPTS="
--ovn-ic-nb-db=tcp:172.30.40.5:6645 \
--ovn-ic-sb-db=tcp:172.30.40.5:6646 \
--ovn-northd-nb-db=tcp:172.30.40.65:6641 \
--ovn-northd-sb-db=tcp:172.30.40.65:6642
"