Fix issue with Entity and Block selecting GUIs.

Items were not selected unless player use right click. Not it will work correctly.

src/main/java/world/bentobox/challenges/panel/util/SelectBlocksGUI.java

@@ -191,9 +191,12 @@ public class SelectBlocksGUI
 					{
 						this.selectedMaterials.remove(material);
 					}
+
+					panel.getInventory().setItem(slot, this.createMaterialButton(material).getItem());
 				}
 				else
 				{
+					this.selectedMaterials.add(material);
 					this.consumer.accept(true, this.selectedMaterials);
 				}
 

src/main/java/world/bentobox/challenges/panel/util/SelectEntityGUI.java

@@ -184,9 +184,12 @@ public class SelectEntityGUI
 					{
 						this.selectedEntities.remove(entity);
 					}
+
+					panel.getInventory().setItem(slot, this.createEntityButton(entity).getItem());
 				}
 				else
 				{
+					this.selectedEntities.add(entity);
 					this.consumer.accept(true, this.selectedEntities);
 				}