Correct docstring param name.

test/functional/rpc_net.py

@@ -34,7 +34,7 @@ def assert_net_servicesnames(servicesflag, servicenames):
     `getpeerinfo` and `getnetworkinfo`.
 
     :param servicesflag: The services as an integer.
-    :param servicesnames: The list of decoded services names, as strings.
+    :param servicenames: The list of decoded services names, as strings.
     """
     if servicesflag & NODE_NETWORK:
         assert "NETWORK" in servicenames