TINY-1454: fixed safari iframe sandbox issue
TINY-1454: fixed safari iframe sandbox issue

danielpunkass/tinymce,tinymce/tinymce,TeamupCom/tinymce,danielpunkass/tinymce,FernCreek/tinymce,FernCreek/tinymce,FernCreek/tinymce,tinymce/tinymce,danielpunkass/tinymce,tinymce/tinymce,TeamupCom/tinymce