Finish an asynchronous lookup issuer operation. See TlsDatabase.lookupCertificateIssuer for more information.
a GAsyncResult
a newly allocated issuer gio.TlsCertificate, or NULL. Use g_object_unref() to release the certificate.
GException on failure.
2.30
Finish an asynchronous lookup issuer operation. See TlsDatabase.lookupCertificateIssuer for more information.