Bind9 zone file should end with a new line

This patchs add a new empty line at the end of the zone template.
Otherwise Bind9 complains with "named[21602]: $PATH/example.net._$ID.zone:18:
file does not end with newline"

Change-Id: Ib73ac32e8e793aa79114879ae0017dbfb725f813
Merge "Bind9 zone file should end with a new line"