[#2006] Add sflphone action sflphone_join_participant

instead of calling dbus_join_participant directly

sflphone-client-gnome/src/actions.c

@@ -841,6 +841,14 @@ sflphone_detach_participant()
     dbus_detach_participant(selectedCall);
 }
 
+    void
+sflphone_join_participant(callable_obj_t* selected_call, callable_obj_t* dragged_call)
+{
+    DEBUG("sflphone join participant from conference");
+
+    dbus_join_participant(selected_call, dragged_call);
+}
+
     void
 sflphone_rec_call()
 {

sflphone-client-gnome/src/contacts/calltree.c

@@ -679,7 +679,7 @@ static void drag_end_cb(GtkWidget * widget, GdkDragContext * context, gpointer d
     g_print("    dragged path %s, call_id %s on previous_id %s\n", dragged_path, call_id, previous_id);
 
     if(selected_call != NULL && dragged_call != NULL)
-        dbus_join_participant(selected_call, dragged_call);
+        sflphone_join_participant(selected_call, dragged_call);
 }