Restart the apply worker if the 'password_required' option is changed.

Restart the apply worker if the 'password_required' option is changed.

The apply worker is restarted if any subscription option that affects the
remote connection was changed. In commit c3afe8cf5a, we added the option
'password_required' which can affect the remote connection, so we should
restart the worker if it was changed.

Author: Amit Kapila
Reviewed-by: Robert Haas
Discussion: https://postgr.es/m/CAA4eK1+z9UDFEynXLsWeMMuUZc1iQkRwj2HNDtxUHTPo-u1F4A@mail.gmail.com
Discussion: https://postgr.es/m/9DFC88D3-1300-4DE8-ACBC-4CEF84399A53@enterprisedb.com