packaging: setup: save network config

Call explicitly setSafeNetworkConfig, ensuring network
configuration persistence after reboot.

Change-Id: I338e0d0152e467448f1ba940f0a1514ce4422b1d
Bug-Url: https://bugzilla.redhat.com/1079633
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>
(cherry picked from commit c0e9c960203276fbcc6326380e37790f13a6fbde)