sharedstorageconf: avoid upgrading local conf file is not valid
sharedstorageconf: avoid upgrading local conf file is not valid

Avoid upgrading local conf file if no data got read from
the shared storage.

Change-Id: Ia9d181b8f68f0156866074b12803db6c982b80ba
Bug-Url: https://bugzilla.redhat.com/1276740
Signed-off-by: Simone Tiraboschi <cb03129c66ba4da7ba7044049d0f43907bf857bb@redhat.com>

oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha