Trivial: Fix wrong comment of _format_servers_list_networks().

The parameter name should be 'networks'.

Change-Id: I140c3d61dccbbec40c14bd7a8f2aeac0eb24384d

Author: tang-chen

openstackclient/compute/v2/server.py

@@ -43,7 +43,7 @@
 def _format_servers_list_networks(networks):
     """Return a formatted string of a server's networks
 
-    :param server: a Server.networks field
+    :param networks: a Server.networks field
     :rtype: a string of formatted network addresses
     """
     output = []