MWEB-974 Fix for uploading images with FormData in Wikia Maps

IE10 and IE11 have a weird way of supporting `FormData`. They throw an error if we're creating instance of `FormData` by passing form instance as a parameter. I found different sources describing solution for it:
* http://stackoverflow.com/questions/18389551/ie10-script5-access-is-denied-on-new-formdata
* https://github.com/styoe/croppic/issues/33
* http://jonhiggins.co.uk/words/formdata-ie10/

This pull request is nothing else as implementation of a workaround on our side for IE10 and IE11.