make the split more forgiving in the "report" chat command

In situations where multiple spaces exist after the URL(s) and before the custom reason, the first element of "argsraw" might have trailing space(s). This change uses string.split()'s behavior with sep=None to regard runs of consecutive whitespace as a single separator (https://docs.python.org/3.3/library/stdtypes.html#str.split). This change also allows for multiple spaces between multiple URLs.

chatcommands.py

@@ -2078,7 +2078,7 @@ def report(msg, args, alias_used="report"):
     alias_used = alias_used or "report"
 
     argsraw = args.split(' "', 1)
-    urls = argsraw[0].split(' ')
+    urls = argsraw[0].split(sep=None)
 
     message_url = "https://chat.{0}/transcript/{1}?m={2}".format(msg._client.host, msg.room.id, msg.id)