Block the /execute ... run datapack command (#361)

* Block the /execute ... run datapack command

The /datapack list command is useless, and the other 2 subcommands (/datapack enable and /datapack disable) can be used to cause huge lag on the server.

* Update ServerCommand.java (partial revert)

src/main/java/pw/kaboom/extras/modules/server/ServerCommand.java

@@ -23,7 +23,7 @@ public final class ServerCommand implements Listener {
     private static final Pattern SELECTOR_PATTERN = Pattern.compile("(?>\\s)*@[aepsr](?>\\s)*");
     private static final Logger LOGGER = JavaPlugin.getPlugin(Main.class).getLogger();
 
-    private static final String[] COMMANDS = { "execute", "clone", "fill", "forceload", "kick",
+    private static final String[] COMMANDS = { "execute", "clone", "datapack", "fill", "forceload", "kick",
             "locate", "locatebiome", "me", "msg", "reload", "save-all", "say", "spreadplayers",
             "stop", "summon", "teammsg", "teleport", "tell", "tellraw", "tm", "tp", "w", "place",
             "fillbiome", "ride" , "tick", "jfr"};