[FIX] web_kanban: _is_quick_create_enabled grouping by day, month or year

When grouping by day, by month or by year on a field date in kanban view,
it raised a traceback.

opw:727266

addons/web_kanban/static/src/js/kanban_view.js

@@ -307,7 +307,8 @@ var KanbanView = View.extend({
         return this.fields_view.fields.active;
     },
     _is_quick_create_enabled: function() {
-        if(!_.contains(['char', 'boolean', 'many2one'], this.fields[this.group_by_field].type)){
+        var group_by_field = this.group_by_field.split(':')[0]
+        if(!_.contains(['char', 'boolean', 'many2one'], this.fields[group_by_field].type)){
             return false;
         }
         if (!this.quick_creatable || !this.is_action_enabled('create'))