KolabMailSettingsHandler: added dummy to private struct
KolabMailSettingsHandler: added dummy to private struct

* added a dummy member to KolabMailSettingsHandlerPrivate
  so the object can be instantiated
  (fixes a 'sizeof(KolabMailSettingsHandlerPrivate) != 0'
  assertion failure)

GNOME/evolution-kolab,GNOME/evolution-kolab