Why are you using SpigotConfig's fully qualified name above, but importing it here anyway?

Your bracket style is inconsistent, on this line, you put it on the same line as the if, but 4 lines above, you put in a new line.

You could also probably simplify these ifs to 
`if((SpigotConfig.tabComplete < 0 || message.length() <= SpigotConfig.tabComplete) && !message.contains(" ")) {`
This would also only check if the message contains " " once. (Left the package out for readability)