[FIX] l10n_fr_pos_cert: use Gui.showPopup instead of show_popup

addons/l10n_fr_pos_cert/static/src/js/pos.js

@@ -16,7 +16,7 @@ models.PosModel = models.PosModel.extend({
     is_french_country: function(){
       var french_countries = ['FR', 'MF', 'MQ', 'NC', 'PF', 'RE', 'GF', 'GP', 'TF'];
       if (!this.company.country) {
-        this.gui.show_popup("error", {
+        Gui.showPopup("ErrorPopup", {
             'title': _t("Missing Country"),
             'body':  _.str.sprintf(_t('The company %s doesn\'t have a country set.'), this.company.name),
         });