Restart the apply worker if the subscription owner's superuser privileges
have been revoked. This is required so that the subscription connection
string gets revalidated and use the password option to connect to the
publisher for non-superusers, if required.
Author: Vignesh C
Reviewed-by: Amit Kapila
Discussion: http://postgr.es/m/CALDaNm2Dxmhq08nr4P6G+24QvdBo_GAVyZ_Q1TcGYK+8NHs9xw@mail.gmail.com