The Gallery Widget incorrectly tried to include the deleted image in the preview. Props westonruter, janak007, afercia, mrasharirfan. Fixes #43139. Built from https://develop.svn.wordpress.org/trunk@44661 git-svn-id: http://core.svn.wordpress.org/trunk@44492 1a063a9b-81f0-0310-95a4-ce76da25c4cd
sanitize_text_field()
::form()