Hi Joe,
I guess you are talking about wysiwyg editor functionality? Like this article for CKeditor?
I'm not aware of a way to remove that, you may be able to find a way in their documentation or you could use browser tools inspect element and maybe find a way to hide the lock by css.
Actually uploading it again and choosing better resizing options seems like a better choice than scaling down a large image with height and width attributes unless its just a small change in size.
Best,
Joe