hamburg: use clients_unique for ffpb, too

modules/ffpb_hamburg.py

@@ -60,7 +60,7 @@ def ffpb_hamburg(bot, trigger):
         return
 
     diff_nodes = hamburg_data['nodes_active'] - stats['nodes_active']
-    diff_clients = hamburg_data['clients'] - stats['clients']
+    diff_clients = hamburg_data['clients'] - stats['clients_unique']
 
     bot.say('Hamburg: {0} Knoten (= PB{1:+g}), {2} Clients (= PB{3:+g})'.format(
         hamburg_data['nodes_active'],