Add a way to dismiss http errors other than "retry" in post creation
When a file upload fails, e.g. if the file is too big (error 413) or if there's a server error (error 500), one gets an error message of this sort:
However, there is no way to dismiss the error other than to click "retry". In cases like 413 retying will not be helpful, since that request will give the same result, but the user has no way to try and remove the problematic images other than to quit the post creation entirely and try again. Ideally, a "dismiss" button should be added next to "retry" to allow the user to make whichever changes they believe will solve the issue then click "post" again.
Edited by Matthieu