profiles: dhclient: allow setting task comm name

dhclient wants to set its thread names to functional names for introspection purposes. Eg.

$ pstree -at 3395
dhclient ens3
  ├─{isc-socket}
  ├─{isc-timer}
  └─{isc-worker0000}

When denied this can result in dhclient breaking and failing to obtain IPv4 addresses.

Fixes: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1918410 Signed-off-by: John Johansen john.johansen@canonical.com