Revert "Use custom async thread execution pool"

This reverts commit a574245bb9.

src/main/java/fr/xephi/authme/initialization/TaskCloser.java

@@ -3,7 +3,6 @@ package fr.xephi.authme.initialization;
 import com.google.common.annotations.VisibleForTesting;
 import fr.xephi.authme.AuthMe;
 import fr.xephi.authme.datasource.DataSource;
-import fr.xephi.authme.service.BukkitService;
 import org.bukkit.scheduler.BukkitScheduler;
 import org.bukkit.scheduler.BukkitWorker;
 
@@ -23,27 +22,22 @@ public class TaskCloser implements Runnable {
     private final Logger logger;
     private final AuthMe plugin;
     private final DataSource dataSource;
-    private final BukkitService bukkitService;
 
     /**
      * Constructor.
      *
      * @param plugin the plugin instance
      * @param dataSource the data source (nullable)
-     * @param bukkitService the bukkit service instance (nullable)
      */
-    public TaskCloser(AuthMe plugin, DataSource dataSource, BukkitService bukkitService) {
+    public TaskCloser(AuthMe plugin, DataSource dataSource) {
         this.scheduler = plugin.getServer().getScheduler();
         this.logger = plugin.getLogger();
         this.plugin = plugin;
         this.dataSource = dataSource;
-        this.bukkitService = bukkitService;
     }
 
     @Override
     public void run() {
-        logger.info("Closing scheduled tasks:");
-
         List<Integer> pendingTasks = getPendingTasks();
         logger.log(Level.INFO, "Waiting for {0} tasks to finish", pendingTasks.size());
         int progress = 0;
@@ -75,16 +69,6 @@ public class TaskCloser implements Runnable {
             tries--;
         }
 
-        logger.info("Closing async tasks...");
-        if(bukkitService != null) {
-            try {
-                bukkitService.closeAsyncPool();
-            } catch (InterruptedException e) {
-                logger.log(Level.WARNING, "Unable to close some async task", e);
-            }
-        }
-
-        logger.info("Closing datasource...");
         if (dataSource != null) {
             dataSource.close();
         }