This fixes an issue in the Website Blog editor where changing a blog cover could fail to open the selection popup after the first use. The editor now keeps the required hidden cover element available instead of removing it, making repeated cover changes work as expected.

Hello, 
    <code>.cover-storage</code> display none set instead of removing <code>.cover-storage</code> node.
Fix this issue https://github.com/odoo/odoo/issues/2470

Thanks