MC-35475: Wrong design for Admin Customer Edit Page on Safari browser

Author: StasKozar

app/code/Magento/Catalog/view/adminhtml/templates/catalog/product/composite/configure.phtml

@@ -38,7 +38,7 @@
     <div id="product_composite_configure_confirmed" class="product_composite_configure_confirmed"></div>
 
     <?php $scriptString = <<<script
-        prodCompConfIframe = document.querySelector("iframe[name='product_composite_configure_iframe']:last-of-type");
+        prodCompConfIframe = document.querySelector("iframe[name='product_composite_configure_iframe']");
         prodCompConfIframe.style.width = 0;
         prodCompConfIframe.style.height = 0;
         prodCompConfIframe.style.border = "0px solid #fff";