Plug some leaks in the GIO tests

Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=666115
Reviewed-by: Matthias Clasen <mclasen@redhat.com>

gio/tests/tls-certificate.c

@@ -308,6 +308,7 @@ main (int   argc,
   g_free (ref.cert_pems[1]);
   g_free (ref.cert_pems[2]);
   g_free (ref.key_pem);
+  g_free (ref.key8_pem);
 
   return rtv;
 }