add permission to plugin.yml and fix safegaurd

src/main/java/tsp/headdb/command/Command_headdb.java

@@ -153,6 +153,7 @@ public class Command_headdb implements CommandExecutor {
 
             Utils.sendMessage(sender, "Updating...");
             Bukkit.getScheduler().runTaskAsynchronously(HeadDB.getInstance(), () -> HeadAPI.getDatabase().update());
+            return true;
         }
 
         Utils.sendMessage(sender, " ");

src/main/resources/plugin.yml

@@ -23,6 +23,7 @@ permissions:
       headdb.favorites: true
       headdb.local: true
       headdb.tagsearch: true
+      headdb.update: true
   headdb.open:
     default: op
   headdb.search:
@@ -35,3 +36,5 @@ permissions:
     default: op
   headdb.tagsearch:
     default: op
+  headdb.update:
+    default: op