Fix Speicher Database + Coding

00-backend/src/main/java/de/htwsaar/webshop/model/ArticleWithImageModel.java

@@ -37,6 +37,6 @@ public class ArticleWithImageModel {
         this.stockExpected = article.getStockExpected();
         this.category = article.getCategory();
         this.rating = article.getRating();
-        this.image = image.getBase64();
+        this.image = image == null ? "" : image.getBase64();
     }
 }