Fixup command registration once again (#3937)

common/src/main/java/com/viaversion/viaversion/commands/defaultsubs/DisplayLeaksSubCmd.java

@@ -27,7 +27,7 @@ import java.util.stream.Collectors;
 public class DisplayLeaksSubCmd implements ViaSubCommand {
     @Override
     public String name() {
-        return "displayleaks <level>";
+        return "displayleaks";
     }
 
     @Override
@@ -35,6 +35,11 @@ public class DisplayLeaksSubCmd implements ViaSubCommand {
         return "Try to hunt memory leaks!";
     }
 
+    @Override
+    public String usage() {
+        return "displayleaks <level>";
+    }
+
     @Override
     public boolean execute(ViaCommandSender sender, String[] args) {
         if (args.length == 1) {