Disable the ability to view cancelled player commands (#2)

* Disable the ability to view cancelled player commands

This would mean that you cannot see the commands of persons who have been ICU controlled.
This would be a nice quality-of-life update because some bots who have been ICU controlled can still clog up CommandSpy even though their commands mean nothing.

* Move check outside the loop, per mathiascode's request

* Remove superfluous check

src/main/java/pw/kaboom/commandspy/Main.java

@@ -66,6 +66,10 @@ public final class Main extends JavaPlugin implements CommandExecutor, Listener
 
 	@EventHandler
 	void onPlayerCommandPreprocess(final PlayerCommandPreprocessEvent event) {
+		if (event.isCancelled()) {
+			return;
+		}
+
 		for (String uuidString : config.getKeys(false)) {
 			UUID uuid = UUID.fromString(uuidString);