virnettlscontexttest fails with GNUTLS 3.0.28

On openSUSE 12.x with GNUTLS 3.0.28, virnettlscontexttest fails. It has
been reported to work from GNUTLS 3.1.11 on Fedora 19. Changed the
constraints on gnutls to 3.1+ for unit test cacert4req.
Signed-off-by: NEric Blake <eblake@redhat.com>

tests/virnettlscontexttest.c

 /*
- * Copyright (C) 2011-2012 Red Hat, Inc.
+ * Copyright (C) 2011-2013 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -265,10 +265,12 @@ mymain(void)
 
     /* Technically a CA cert with basic constraints
      * key purpose == key signing + non-critical should
-     * be rejected. GNUTLS < 3 does not reject it and
+     * be rejected. GNUTLS < 3.1 does not reject it and
      * we don't anticipate them changing this behaviour
      */
-    DO_CTX_TEST(true, cacert4req.filename, servercert4req.filename, GNUTLS_VERSION_MAJOR >= 3);
+    DO_CTX_TEST(true, cacert4req.filename, servercert4req.filename,
+                (GNUTLS_VERSION_MAJOR == 3 && GNUTLS_VERSION_MINOR >= 1) ||
+                GNUTLS_VERSION_MAJOR > 3);
     DO_CTX_TEST(true, cacert5req.filename, servercert5req.filename, true);
     DO_CTX_TEST(true, cacert6req.filename, servercert6req.filename, true);