Slight cleanup and better support for server reloads

bungee/src/main/java/me/lucko/luckperms/LPBungeePlugin.java

@@ -52,6 +52,11 @@ public class LPBungeePlugin extends Plugin implements LuckPermsPlugin {
         }
     }
 
+    @Override
+    public void onDisable() {
+        datastore.shutdown();
+    }
+
     @Override
     public String getVersion() {
         return VERSION;