MB-10840 Change janitor_agent's applied states on delete_vbucket.

Because otherwise subsequent {update_vbucket_states, *} will overwrite
the state for this vbucket in capi_set_view_manager.

Change-Id: I85a7f8c15040878f1ad0282b41f3edf3e29d24c0
Reviewed-on: http://review.couchbase.org/35745
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>