Fix rpc reconnection.

Set rpc_con to False in restart_rpc_connection.

ccnode/node.py

@@ -290,6 +290,9 @@ class MainLoop(object):
         if not self.rpc_connected:
             return
 
+        # clear connection
+        self.rpc_con = None
+
         logger.error('Lost connection to the cc-server, will attempt'
                      ' reconnection')
 
@@ -299,8 +302,6 @@ class MainLoop(object):
         self.reconnect.start()
 
     def restart_rpc_connection_cb(self, *args):
-        # clear connection
-        self.rpc_con = None
         # attempt to connect to the cc-server again
         self.connect = RPCStartHandler(self)
         self.connect.start()