OS-479, DHCP service workflow fixes

    * dhcp_members was asigned but infoblox services wasnt restarted
    * dns server wasnt assigned in infoblox DHCP service
AFAIR relay_ip value returned by NIOS WAPI is a string of comma-separated values, e.g. "10.39.123.1,10.39.123.2,10.39.123.3". Are you sure this will work?