[master] 25c7cc5f9 doc: Mention the varnishtest change

[Dridi Boukelmoune]

commit 25c7cc5f9ac41383fc718153514f957cbf023241
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Fri Sep 11 12:04:45 2020 +0200

    doc: Mention the varnishtest change
    
    The only user-visible change for this release.

diff --git a/doc/sphinx/whats-new/changes-trunk.rst b/doc/sphinx/whats-new/changes-trunk.rst
index 4b51473ac..da9782274 100644
--- a/doc/sphinx/whats-new/changes-trunk.rst
+++ b/doc/sphinx/whats-new/changes-trunk.rst
@@ -121,7 +121,9 @@ counters.
 varnishtest
 ===========
 
-**XXX changes concerning varnishtest(1) and/or vtc(7)**
+The ``process -expect-text`` command will wait an order of magnitude longer
+for the text to appear. It used to be too sensitive to any kind of timing
+disruption.
 
 Changes for developers and VMOD authors
 =======================================