Conflict with WPSeo

You can hide the message yourself using the White Label CMS plugin and adding the below css to the admin settings section:

.wrap div.updated, .wrap div.error, .media-upload-form div.error { display: none; }

When using the above method the nag box still shows for a fraction of a second before disappearing but it works without conflict since it simply uses css to hide the message.

Cheers