Crash reports imply the `certBackend` we extract in
QSslCertificate_from_CERT_CONTEXT is null, which means that
something went wrong when parsing the certificate data we get from
the certificate chain.
We assume the rest is okay since it must be inside the bounds of the
length of the chain.
It's not clear why the certificate would be invalid, but it's better
to avoid the crash for now.
Pick-to: 6.5 6.6
Task-number: QTBUG-118569
Change-Id: I76ce07fc38bf82ef5c93097d839724ddee1edeef
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
91fe6fb2e1