tests: extend workaround for gnutls private key loading failure

In gnutls 3.4.3 there is a regression in the loading of private
keys via gnutls_x509_privkey_import. We already have a workaround
to deal with failures on older gnutls, but the error code that
the new gnutls returns is different. Extend the workaround so that
is checks for GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE too.

See also gnutls https://bugzilla.redhat.com/show_bug.cgi?id=1250020Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

tests/virnettlshelpers.c

@@ -84,7 +84,8 @@ static gnutls_x509_privkey_t testTLSLoadKey(void)
 
     if ((err = gnutls_x509_privkey_import(key, &data,
                                           GNUTLS_X509_FMT_PEM)) < 0) {
-        if (err != GNUTLS_E_BASE64_UNEXPECTED_HEADER_ERROR) {
+        if (err != GNUTLS_E_BASE64_UNEXPECTED_HEADER_ERROR &&
+            err != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
             VIR_WARN("Failed to import key %s", gnutls_strerror(err));
             abort();
         }