Export objects prior to bus name grab

The default behavior in pyphosphor changed such that ObjectManager
and Properties signals are not emitted by default.  Enable signals
just prior to bus name grab.

Change-Id: I27a2de4b60482dd843702396f33c7cdccaf17277
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/pychassisctl/chassis_control.py b/pychassisctl/chassis_control.py
index 71bf533..8a95ba6 100755
--- a/pychassisctl/chassis_control.py
+++ b/pychassisctl/chassis_control.py
@@ -241,6 +241,8 @@
     bus = get_dbus()
     obj = ChassisControlObject(bus, OBJ_NAME)
     mainloop = gobject.MainLoop()
+
+    obj.unmask_signals()
     name = dbus.service.BusName(DBUS_NAME, bus)
 
     print "Running ChassisControlService"