db: Adding default values to ssh fields

Old vds_static raws should have values for ssh username (root as default)
and ssh port (22 as defaults) after upgrade to 3.3. If the values are null,
the update script set the defaults.

Change-Id: I0ae6f434edcacce5039107b221bd86ccaab92309
Signed-off-by: Yaniv Bronhaim <ybronhei@redhat.com>