[glib-networking] Add a comment

[Michael Catanzaro <mcatanzaro src gnome org>]

commit ae2ec355491c24d8cf07f843cd4300e41b7dfd3a
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Sun Mar 11 15:14:45 2018 -0500

    Add a comment

 tls/gnutls/gtlsconnection-gnutls.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/tls/gnutls/gtlsconnection-gnutls.c b/tls/gnutls/gtlsconnection-gnutls.c
index e5ab896..4a8506b 100644
--- a/tls/gnutls/gtlsconnection-gnutls.c
+++ b/tls/gnutls/gtlsconnection-gnutls.c
@@ -1882,6 +1882,11 @@ handshake_thread (GTask        *task,
         }
     }
 
+  /* This calls the finish_handshake code of GTlsClientConnectionGnutls
+   * or GTlsServerConnectionGnutls. It has nothing to do with
+   * GTlsConnenctionGnutls's own finish_handshake function, which still
+   * needs to be called at this point.
+   */
   G_TLS_CONNECTION_GNUTLS_GET_CLASS (gnutls)->finish_handshake (gnutls, &error);
 
   if (error)