update host

exercises/python-rpc/client.py

 import xmlrpc.client
 
-server = xmlrpc.client.ServerProxy("http://localhost:8000")
+server = xmlrpc.client.ServerProxy("http://0.0.0.0:8000")
 with server as proxy:
     result = proxy.square(5)
     print("[RPC] The square of 5 is:", result)

exercises/python-rpc/server.py

@@ -7,7 +7,7 @@ class MyServer:
     def cube(self, x):
         return x * x * x
 
-server = xmlrpc.server.SimpleXMLRPCServer(("localhost", 8000))
+server = xmlrpc.server.SimpleXMLRPCServer(("0.0.0.0", 8000))
 print("Listening on port 8000...")
 server.register_instance(MyServer())
 server.serve_forever()