Workbench loads CA certs on Red Hat.

Workbench loads CA certs on Red Hat.

This has the same rationale and logic as #6432 and
9b910084faf3db6fa2071af604620e7d45d12a6c, applied to Workbench.

Changing from `/etc/ssl/certs` to `/etc/ssl/certs/ca-certificates.crt`
is safe, because add_trust_ca accepts either a directory with hashed
certs, or a file with multiple certs.  On Debian, the latter path is a
single file built from the hashed certs in the former, so this is
functionally identical there, and more predictable on Red Hat (where I
don't know what it's doing).

No issue #.