da053e34 broke the tls-certificates test by requiring the backend to
implement g_tls_certificate_verify() (which the test TLS backend
didn't). Add a trivial implementation to make the test pass again;
we'll need something more complicated when we add tests that are
supposed to get errors.
* In order to add contstruct properties to an abstract base
calls, and retain ABI stability, the base class must add a
default implementation of those properties.
* We cannot add a default implementation of certificate-bytes
or private-key-bytes since certificate and private-key properties
are writable on construct-only.
This reverts commit 541c985869.
https://bugzilla.gnome.org/show_bug.cgi?id=682081
