The priviledge separation mode has several downsides:
- it's incompatible with alternative memory allocators, including
graphene-hardened;
- it needs an unreleased patch to fix a crash;
- it results in none less than 6 subprocesses running at any time,
increasing the memory usage;
- the privileged process (albeit not doing any networking related
tasks) is still running as root, so it has complete access to the
system.
Let's disable this by default and instead run dhcpcd as an unpriviledge
user with only the necessary capabilities.