templates: your must use field.html_name to construct label for attributes

compte_agglo_montpellier/templates/passerelle_register_plugin/plugin.html

@@ -15,7 +15,7 @@
              {% for choice in form.all_choices %}
                {% for checkbox in field %}
                  {% if checkbox.choice_value == choice %}
-                 <td>{{ checkbox.tag }}<label for="{{field.name}}_0">{{ field.label }}</label></td>
+                 <td>{{ checkbox.tag }}<label for="{{field.html_name}}_0">{{ field.label }}</label></td>
                  {% endif %}
                {% endfor %}
              {% endfor %}