Then points without the message

--We were unable to compile and test this ourselves, but this is a small change--

Basically, when using `then points`, it got slightly annoying how it had to include a message to be sent to the player. I wanted to apply this to every message sent, so as to act as a spam filter to stop too many messages in a certain amount of time. This small change just means that no message is sent if the string is empty.
Personally, I don't know why `then points` needs to send a message to the player when `then warn` does exactly the same thing.
But hey, not my plugin. If you have a different solution for this, feel free to say.