Entering no parameter into @[STAT] command generates an error

[thebuilderbob1]

Describe the bug
Using a @[STAT] command e.g '@ STR' without any parameters will cause an error in GeneralChatHandler.java

To Reproduce
Steps to reproduce the behavior:

1. Run the server and login
2. When in-game, type: '@ STR'
3. Produces error in GeneralChatHandler - ArrayOutOfBoundsException

Expected behavior
I expected the server to handle input with zero parameters.
I expected a message for the player using the command, that it isn't possible to use the command without any parameters or something like that.

Screenshots
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