ctrl2cgi: explicitly ignore arguments to lambda function

Make sure that we don't fail regardless of number of arguments given.

Change-Id: I44035323b70f04eb8f5dc12123cb708f53eba188
diff --git a/scripts/ctrl2cgi.py b/scripts/ctrl2cgi.py
index bdbd5c5..471cf23 100755
--- a/scripts/ctrl2cgi.py
+++ b/scripts/ctrl2cgi.py
@@ -108,7 +108,7 @@
         loc = l.split('.')
         t_type = loc[-1]
         p = partial(lambda a, i: a[i] if len(a) > i else None, loc) # parse helper
-        method = getattr(self, 'handle_' + t_type.replace('-', ''), lambda: "Unhandled %s trap" % t_type)
+        method = getattr(self, 'handle_' + t_type.replace('-', ''), lambda *_: "Unhandled %s trap" % t_type)
         method(p(1), p(3), p(5), p(7), r) # we expect net.0.bsc.666.bts.2.trx.1 format for trap prefix
 
     def ctrl_SET_REPLY(self, data, _, v):