[FIX] web: error on mobile when kanban groupedBy change

Sometimes when the groupedBy view is changed the index of the current
active column overflow the kanban tabs length.

In this commit this effect is avoided by resetting the active
kanban column to the first one when the groupedBy is changed.

Task: 1893168

addons/web/static/src/js/views/kanban/kanban_renderer_mobile.js

@@ -201,7 +201,8 @@ KanbanRenderer.include({
         var self = this;
         return this._super.apply(this, arguments).then(function () {
             if (self.state.groupedBy.length) {
-                return self._moveToGroup(self.activeColumnIndex);
+                // force first column for kanban view, because the groupedBy can be changed
+                return self._moveToGroup(0);
             }
         });
     },