Issue saving changes

Hi Pierre,

Thanks for this very useful plugin.

I’ll like to add a CSS class to the text displayed when oEmbed are blocked.
I change the content of input then save the page, the message saying that the changes are saved appears, but my changes do not seem to have been saved.

See https://gyazo.com/42d5f34b7fb8a0e9f9cac0131b73be05 to illustrate.

Regards,