Until now, whenever NetworkManager gets reloaded/restarted/lease
refresh, it would override the /etc/resolv.conf file with the
nameservers and related it gets from the network.
This patch ensures this won't happen ever again.
Note: this is a corrected version of
I92bc12b8f712e28962d24dd6474cfce22b81222c
that was reverted due to indentation + use of ConfigParser issues.
Change-Id: I48560641238911154cc9f353f707a9374613e51a