Fix shutdown in case of errors during initialization

Summary:
This backports prevents an error that could throw a segfault at shutdown
if initialization fails in some cases. This will avoid introducing a bug
when backporting PR11781 in a later diff.

Backport of core PR11783

Depends on D2392

Test Plan:

make check

Further testing will be part of the test plan of PR11781 backport, as I
am not aware of any other method to throw the error.

Reviewers: #bitcoin_abc, deadalnix, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: teamcity, schancel

Differential Revision: https://reviews.bitcoinabc.org/D2393