Add title attribute for iframe to suppress accessibility errors (#4407)

adapters/oidc/js/src/main/resources/keycloak.js

@@ -843,6 +843,7 @@
             }
 
             iframe.setAttribute('src', src );
+            iframe.setAttribute('title', 'keycloak-session-iframe' );
             iframe.style.display = 'none';
             document.body.appendChild(iframe);