Fix getting MD5 hash for configuration tar
Fix getting MD5 hash for configuration tar

Use the _enforce_vdsm_user method to execute
the md5hash command.

Change-Id: If23a79478f8c7f782b6fe8135118bee72fb8f776
Bug-Url: https://bugzilla.redhat.com/1301681
Signed-off-by: Jenny Tokar <1acd0034267bdb7277525cbe7ae83185c669ca44@redhat.com>

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