In init_view_plugin we affected something to
vpd->configure.
It is a function defined as :
mstatic GtkWidget* configure(ViewPluginData *vpd);
It is used in the 'configure' box inside Gaby. Since you don't have anything to
configure you may simply type (or affect NULL to the
variable :
mstatic GtkWidget* configure(ViewPluginData *vpd)
{
return NULL;
}