[FIX] test_main_flows: don't click behind modal

In the main_flow_tour, we edit a related record of a many2one in a
one2many. A modal is displayed and we make some changes. We
then click on 'Save' in the dialog. The next step is to add a new record
in the one2many, so we click on 'Add an item'. However, we didn't
wait for the modal to be closed before clicking, which is actually not
possible in practice (because of the modal backdrop).

This made the tour fail when run from the browser, since commit
c300e5e, which produces a redraw of the line containing the
many2one that has been edited.

This rev. ensures that we wait for the modal to be closed before
adding a second record.

odoo/addons/test_main_flows/static/src/js/tour.js

@@ -126,7 +126,7 @@ tour.register('main_flow_tour', {
 }, {
 // Add second component
     trigger: ".o_field_x2many_list_row_add > a",
-    in_modal: false,
+    extra_trigger: "body:not(.modal-open)",
     content: _t("Click here to add some lines."),
     position: "bottom",
 }, {