engine: Use callers error dialog when launching windows

This gives proper dialog placement.

src/virtManager/systray.py

@@ -22,6 +22,8 @@ import gobject
 import gtk
 import gtk.glade
 
+from virtManager.error import vmmErrorDialog
+
 try:
     import appindicator
 except:
@@ -71,6 +73,11 @@ class vmmSystray(gobject.GObject):
 
         self.config = config
         self.engine = engine
+        self.topwin = None
+        self.err = vmmErrorDialog(None,
+                                  0, gtk.MESSAGE_ERROR, gtk.BUTTONS_CLOSE,
+                                  _("Unexpected Error"),
+                                  _("An unexpected error occurred"))
 
         self.conn_menuitems = {}
         self.conn_vm_menuitems = {}