Converted protected_branch_edit.js to use axios

app/assets/javascripts/protected_branches/protected_branch_edit.js

-/* eslint-disable no-new */
-import Flash from '../flash';
+import flash from '../flash';
+import axios from '../lib/utils/axios_utils';
 import ProtectedBranchAccessDropdown from './protected_branch_access_dropdown';
 
 export default class ProtectedBranchEdit {
@@ -38,12 +38,7 @@ export default class ProtectedBranchEdit {
     this.$allowedToMergeDropdown.disable();
     this.$allowedToPushDropdown.disable();
 
-    $.ajax({
-      type: 'POST',
-      url: this.$wrap.data('url'),
-      dataType: 'json',
-      data: {
-        _method: 'PATCH',
+    axios.patch(this.$wrap.data('url'), {
       protected_branch: {
         merge_access_levels_attributes: [{
           id: this.$allowedToMergeDropdown.data('access-level-id'),
@@ -54,13 +49,14 @@ export default class ProtectedBranchEdit {
           access_level: $allowedToPushInput.val(),
         }],
       },
-      },
-      error() {
-        new Flash('Failed to update branch!', 'alert', document.querySelector('.js-protected-branches-list'));
-      },
-    }).always(() => {
+    }).then(() => {
       this.$allowedToMergeDropdown.enable();
       this.$allowedToPushDropdown.enable();
+    }).catch(() => {
+      this.$allowedToMergeDropdown.enable();
+      this.$allowedToPushDropdown.enable();
+
+      flash('Failed to update branch!', 'alert', document.querySelector('.js-protected-branches-list'));
     });
   }
 }