[libdazzle] dock-item: set va marshaller for signal

[Christian Hergert <chergert src gnome org>]

commit a1de4020559add0f9ec124803c10c03f491d3c87
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jun 25 18:48:17 2018 -0700

    dock-item: set va marshaller for signal

 src/panel/dzl-dock-item.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/panel/dzl-dock-item.c b/src/panel/dzl-dock-item.c
index 0d783aa..1a87836 100644
--- a/src/panel/dzl-dock-item.c
+++ b/src/panel/dzl-dock-item.c
@@ -161,6 +161,9 @@ dzl_dock_item_default_init (DzlDockItemInterface *iface)
                   G_STRUCT_OFFSET (DzlDockItemInterface, manager_set),
                   NULL, NULL, NULL,
                   G_TYPE_NONE, 1, DZL_TYPE_DOCK_MANAGER);
+  g_signal_set_va_marshaller (signals [MANAGER_SET],
+                              G_TYPE_FROM_INTERFACE (iface),
+                              g_cclosure_marshal_VOID__OBJECTv);
 }
 
 /**