Prevent removal of customize_changeset_status if the status are not same

[mohdsayed]

In https://github.com/xwp/wp-customize-snapshots/pull/111 we had removed isSameStatus check before removing the customize_changeset_status because of which empty status was being sent when you add or change to a new status and hence throwing error for the first time in schedule. Fixed

[mohdsayed]

Ready for review.