Properly read approvalPending from dataset.

app/assets/javascripts/merge_request_widget/widget_store.js.es6

@@ -23,7 +23,7 @@
 
     initWidgetState() {
       this.assignToData('showApprovals', false);
-      this.assignToData('disableAcceptance', Boolean(this.rootEl.dataset.approvalPending));
+      this.assignToData('disableAcceptance', this.rootEl.dataset.approvalPending === 'true');
     }
 
     initApprovals() {

app/views/projects/merge_requests/widget/_open.html.haml

 - content_for :page_specific_javascripts do
   = page_specific_javascript_tag('merge_request_widget/widget_bundle.js')
 
-#merge-request-widget-app.mr-state-widget{ 'data-endpoint'=> merge_request_path(@merge_request), 'data-approval-pending' => !@merge_request.approved? ? 'true' : 'false' }
+#merge-request-widget-app.mr-state-widget{ 'data-endpoint'=> merge_request_path(@merge_request), 'data-approval-pending' => (!@merge_request.approved?).to_s }
   = render 'projects/merge_requests/widget/heading'
   .mr-widget-body
     -# After conflicts are resolved, the user is redirected back to the MR page.