[Github Issue] kresd: support local config file
#### **DO NOT EDIT HERE!** Copy from https://github.com/CZ-NIC/turris-os-packages/issues/7
There's currently no way to change the kresd config file without modifying the init script (changes which will be overwritten each time kresd is updated).
This patch adds support for local configs (similarly to how dnsmasq allows both /etc/dnsmasq.conf and uci config).