Ordinarily, dhcpcd will put resolv.conf back the way it was when it disconnects.  Because
Byzantium Linux disables the 20-resolv.conf hook script because we set up our own DNSes,
this also disables putting resolv.conf back when dhcpcd is terminated.  So, we do what the
20-resolv.conf script would do anyway, which is erase the contents of the file.

Signed-off-by: The Doctor <drwho@virtadpt.net>
Merge branch 'master' of https://github.com/Byzantium/Byzantium