Fix compatibility issues

src/main/java/fr/xephi/authme/AuthMe.java

@@ -24,7 +24,6 @@ import org.bukkit.scheduler.BukkitTask;
 import org.apache.logging.log4j.LogManager;
 
 import org.mcstats.Metrics;
-import com.comphenix.protocol.ProtocolLibrary;
 import com.earth2me.essentials.Essentials;
 import com.onarandombox.MultiverseCore.MultiverseCore;
 import net.milkbowl.vault.permission.Permission;
@@ -474,7 +473,7 @@ public class AuthMe extends JavaPlugin {
         if (Settings.protectInventoryBeforeLogInEnabled) {
             if (server.getPluginManager().isPluginEnabled("ProtocolLib")) {
                 inventoryProtector = new AuthMeInventoryListener(this);
-                ProtocolLibrary.getProtocolManager().addPacketListener(inventoryProtector);
+                inventoryProtector.register();
             } else {
                 ConsoleLogger.showError("WARNING!!! The protectInventory feature requires ProtocolLib! Disabling it...");
                 Settings.protectInventoryBeforeLogInEnabled = false;

src/main/java/fr/xephi/authme/listener/AuthMeInventoryListener.java

@@ -60,6 +60,10 @@ public class AuthMeInventoryListener extends PacketAdapter {
         }
     }
 
+    public void register() {
+        ProtocolLibrary.getProtocolManager().addPacketListener(this);
+    }
+
     public void sendInventoryPacket(Player player) {
         ProtocolManager protocolManager = ProtocolLibrary.getProtocolManager();
         PacketContainer inventoryPacket = protocolManager.createPacket(PacketType.Play.Server.WINDOW_ITEMS);