another fix for IE11 (#1102)

CHANGES.md

@@ -19,6 +19,7 @@
 - Spoiler messages didn't include the message author's name.
 - Documentation includes utf-8 charset to make minfied versions compatible across platforms. #1017
 - #1026 Typing in MUC shows "Typing from another device"
+- #1039 Multi-option data form elements not shown and saved correctly
 
 ### API changes
 - `_converse.api.vcard.get` now also accepts a `Backbone.Model` instance and

src/utils/core.js

@@ -617,7 +617,7 @@
          *      (String) selector - the selector they should be matched
          *          against.
          */
-        return _.filter(el.children, _.partial(u.matchesSelector, _, selector));
+        return _.filter(el.childNodes, _.partial(u.matchesSelector, _, selector));
     };
 
     u.contains = function (attr, query) {

src/utils/form.js

@@ -98,7 +98,7 @@
                         return tpl_select_option({
                             'value': value,
                             'label': option.getAttribute('label'),
-                            'selected': values.includes(value),
+                            'selected': _.includes(values, value),
                             'required': !_.isNil(field.querySelector('required'))
                         })
                     }