Fix libvirt deconnect

cloudcontrol/node/hypervisor/__init__.py

@@ -173,7 +173,7 @@ class Handler(HostHandler):
         # remove handlers related to libvirt
         for handler in self.virt_handlers:
             del self.rpc_handler[handler]
-            self.main.remove_handler[handler]
+            self.main.remove_handler(handler)
         # launch connection timer
         self.timer.start()