remove special handling of input[type=image][formaction], fixes #2177

Closes #2177

Merge request studip/studip!1405

resources/assets/javascripts/bootstrap/forms.js

@@ -127,15 +127,6 @@ STUDIP.ready((event) => {
 });
 
 
-// simulate formaction attribute for input[type=image] in IE11
-$(document).on('click', 'input[type=image][formaction]', function() {
-    if ($(this).attr('data-confirm') === undefined) {
-        $(this)
-            .closest('form')
-            .attr('action', $(this).attr('formaction'));
-    }
-});
-
 // Use select2 for crossbrowser compliant select styling and
 // handling
 $.fn.select2.amd.define('select2/i18n/de', [], function() {