templates: in passerelle_register_plugin/plugin.html update template for the submit button

compte_agglo_montpellier/templates/passerelle_register_plugin/plugin.html

@@ -23,6 +23,6 @@
          {% endfor %}
       </tbody>
     </table>
-    <input type="submit" name="{{ submit }}" value="{% trans "Validate" %}"/>
+    <input type="submit" name="{{ submit_name }}" value="{{ submit_value }}"/>
   </form>
 </div>