Add missing return in EventListeners

src/main/java/com/alttd/playershops/listener/PlayerListener.java

@@ -65,6 +65,9 @@ public class PlayerListener extends EventListener {
 
     @EventHandler(ignoreCancelled = true, priority = EventPriority.HIGHEST)
     public void onSignChange(SignChangeEvent event) {
+        if(!this.isRegistered)
+            return;
+
         Block block = event.getBlock();
 
         if (!(block.getState() instanceof Sign)) return;
@@ -77,6 +80,9 @@ public class PlayerListener extends EventListener {
 
     @EventHandler(ignoreCancelled = true, priority = EventPriority.HIGHEST)
     public void onShopCreation(SignChangeEvent event) {
+        if(!this.isRegistered)
+            return;
+
         Block b = event.getBlock();
         Player player = event.getPlayer();
         if (!(b.getState() instanceof Sign))

src/main/java/com/alttd/playershops/listener/ShopListener.java

@@ -24,7 +24,8 @@ public class ShopListener extends EventListener {
 
     @EventHandler(ignoreCancelled = true)
     public void onEntityExplosion(EntityExplodeEvent event) {
-        if(!this.isRegistered) return;
+        if(!this.isRegistered)
+            return;
         // This might be heavy when tnt is chained, would it be better to expand the unbreakable block api in galaxy and use that?
         // No need for slow bukkit events eating up cpu and memory
         Iterator<Block> blockIterator = event.blockList().iterator();

src/main/java/com/alttd/playershops/listener/TransactionListener.java

@@ -32,6 +32,9 @@ public class TransactionListener extends EventListener {
 
     @EventHandler(ignoreCancelled = true)
     public void onShopSignClick(PlayerInteractEvent event) {
+        if(!this.isRegistered)
+            return;
+
         if (event.getHand() == EquipmentSlot.OFF_HAND) {
             return;
         }