Remove double click prevention

[andre-dasilva]

The preventDoubleFormSubmissions() does not work well with django admin actions.

If I for example download a pdf file from django admin action (return a HttpResponse in the action) then the button does not work after the first execution (because of the preventDoubleFormSubmissions()). Only after a reload it will work again, which can be annoying for users.

So I would disable / remove this function. Was there a reason for it? The normal django admin does not do this.