Catch non 200 response codes of WhatsApp tool

src/main/java/de/jeyp91/whatsapp/WhatsAppNotifier.java

@@ -51,8 +51,12 @@ public class WhatsAppNotifier {
                 .build();
         boolean success = false;
         try {
-            client.send(req, HttpResponse.BodyHandlers.ofString()).body();
-            success = true;
+            int responseCode = client.send(req, HttpResponse.BodyHandlers.ofString()).statusCode();
+            if (responseCode != 200) {
+                logger.error("Failed to send WhatsApp message. Response code: " + responseCode);
+            } else {
+                success = true;
+            }
         } catch (Exception e) {
             logger.error("Failed to send WhatsApp message: " + e.getMessage());
         }