- Since 3.0MP9 the email related column in ad_client table were no longer
  used (and instead the ones in c_poc_configuration).
  However the change in MP9 did not mark the columns as deprecated. Do
  that now to make it more visible in code (i.e. src-gen).
- One of the columns smtphost has also still stored into the HttpSession
  under the #Client_SMTP name. Checking across all published modules +
  gitlab.com/openbravo/* did not find any user.
  So stop storing that deprecated column value in the session.