fixed double item dropping and fixed exitWorld command

src/main/java/eu/mhsl/minecraft/pixelblocks/commands/ExitWorldCommand.java

@@ -23,7 +23,7 @@ public class ExitWorldCommand implements CommandExecutor {
 
             PixelBlock currentPixelBlock = PixelBlock.getPixelBlockFromBlockWorld(playerWorld);
             Objects.requireNonNull(currentPixelBlock);
-            p.teleport(currentPixelBlock.getLastEntryLocation());
+            currentPixelBlock.exitBlock(p);
         }
         return true;
     }

src/main/java/eu/mhsl/minecraft/pixelblocks/pixelblock/PixelBlock.java

@@ -180,6 +180,7 @@ public class PixelBlock {
 //    }
 
     public void destroy(Player destroyedBy) {
+        if(!this.exists) return;
         if(Main.configuration.onlyBreakableByOwner() && !destroyedBy.getUniqueId().equals(ownerUUID)) {
             destroyedBy.sendMessage("Dieser Pixelblock gehört nicht dir!");
             return;