[glib-networking] Add a reminder comment about gnutls_set_default_priority_append()

[Michael Catanzaro <mcatanzaro src gnome org>]

commit c609832d803f0facd0a427555ec9981ee5bd1d24
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Sun Nov 11 19:58:08 2018 -0600

    Add a reminder comment about gnutls_set_default_priority_append()

 tls/gnutls/gtlsconnection-gnutls.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/tls/gnutls/gtlsconnection-gnutls.c b/tls/gnutls/gtlsconnection-gnutls.c
index e975419..c4ba01c 100644
--- a/tls/gnutls/gtlsconnection-gnutls.c
+++ b/tls/gnutls/gtlsconnection-gnutls.c
@@ -286,6 +286,9 @@ g_tls_connection_gnutls_init (GTlsConnectionGnutls *gnutls)
 /* First field is "fallback", second is "allow unsafe rehandshaking" */
 static gnutls_priority_t priorities[2][2];
 
+/* TODO: Get rid of this in favor of gnutls_set_default_priority_append()
+ * when upgrading to GnuTLS 3.6.3.
+ */
 #define DEFAULT_BASE_PRIORITY "NORMAL:%COMPAT"
 
 static void