IPsec mobile clients DNS enhancement
linked to #8292
changing DNS from attr plugin to rightdns as of strongswan wiki:
DNS servers and other attributes can be assigned by plugins (e.g. the attr plugin) or since 5.0.1 directly in ipsec.conf by use of the rightdns option. In swanctl.conf each pool in the pools section may define a list of attributes to assign to clients.
Now each client can have an individual assigned DNS.