[1128151] Error while upgrading from JON 3.1.2 to 3.3: [rhq.autoinstall.server.admin.password] must exist and be set to a valid string value
Ensure that the property gets a string value assigned during upgrade so that
the properties file passes validation. The dummy value is "ignored-on-upgrade",
the rhqadmin user will already exist in an upgraded server's DB.

(cherry picked from commit d83319b26276e4e24b197252dfecc4127311a0e2)
Signed-off-by: Jay Shaughnessy <jshaughn@redhat.com>