fix: shopify interceptor class cast error

src/main/java/au/com/royalpay/payment/manage/shopify/support/ShopifyRequestInfoInterceptor.java

@@ -15,6 +15,9 @@ public class ShopifyRequestInfoInterceptor extends HandlerInterceptorAdapter {
 
     @Override
     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
+        if (!(handler instanceof HandlerMethod)){
+            return super.preHandle(request, response, handler);
+        }
         Method method = ((HandlerMethod) handler).getMethod();
 
         if(HttpMethod.GET.matches(request.getMethod())) {