Fix typo

util/util.py

@@ -123,7 +123,7 @@ def get_challenge_from_args_or_channel(database, args, channel_id):
     """
     Helper method for getting a Challenge either from arguments or current channel.
     Return the corresponding Challenge if called from a challenge channel.
-    Return the Challenge correpsonding to the first argument if called from the
+    Return the Challenge corresponding to the first argument if called from the
     CTF channel.
     Return None if no Challenge can be found.
     """