Revert "Change checkboxes to GOVUK frontend"

app/templates/views/service-settings/sms-sender/add.html

@@ -1,5 +1,6 @@
 {% extends "withnav_template.html" %}
 {% from "components/textbox.html" import textbox %}
+{% from "components/checkbox.html" import checkbox %}
 {% from "components/page-header.html" import page_header %}
 {% from "components/page-footer.html" import page_footer %}
 {% from "components/form.html" import form_wrapper %}
@@ -22,7 +23,9 @@
       hint='Up to 11 characters, letters, numbers and spaces only'
     ) }}
     {% if not first_sms_sender %}
-      {{ form.is_default }}
+      <div class="form-group">
+        {{ checkbox(form.is_default) }}
+      </div>
     {% endif %}
     {{ page_footer('Save') }}
   {% endcall %}