Removed needless setter

src/main/java/de/rwu/easydrop/api/dto/ProductDTO.java

@@ -39,13 +39,6 @@ public class ProductDTO {
         return productId;
     }
 
-    /**
-     * @param newProductId the productId to set
-     */
-    public void setProductId(final String newProductId) {
-        this.productId = newProductId;
-    }
-
     /**
      * Current product price per piece in Euro.
      */