Update _base.css.scss

Removing default support for date picker UI theme active admin

Author: rakesh410

app/assets/stylesheets/active_admin/_base.css.scss

@@ -8,7 +8,7 @@
 @import "active_admin/forms";
 @import "active_admin/components/comments";
 @import "active_admin/components/flash_messages";
-@import "active_admin/components/date_picker";
+/*@import "active_admin/components/date_picker";*/
 @import "active_admin/components/popovers";
 @import "active_admin/components/tables";
 @import "active_admin/components/batch_actions";