Otherwise individual sockets will still load system certificates when
a chain doesn't match against the configured CA certificates.
That's not intended behavior, since specifically setting the CA
certificates means you don't want the system certificates to be used.
Follow-up to/amends ada2c573c1
This is potentially a breaking change because now, if you ever add a
CA to the default config, it will disable loading system certificates
on demand for all sockets. And the only way to re-enable it is to
create a null-QSslConfiguration and set it as the new default.
Pick-to: 6.5 6.2 5.15
Change-Id: Ic3b2ab125c0cdd58ad654af1cb36173960ce2d1e
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
57ba6260c0