The code img[src="https://gravityforms.s3.amazonaws.com/banners/gravity-forms-unregistered-2.png"] { display: none;}
is working, if you copy the code from posts above and paste, you will have problem with ” characters, make sure it correct, you can copy my code and paste
I install this plugin https://wordpress.org/plugins/admin-css-mu/ then enter the css code above and eveything is ok
Hope this help
