[evolution] Mention 'Fall back to threading messages by subject' preference

[Andre Klapper <aklapper src gnome org>]

commit 89b3b83026f96fa1885859b12feacfcd19cc3514
Author: Andre Klapper <a9016009 gmx de>
Date:   Mon Sep 11 14:38:00 2017 +0200

    Mention 'Fall back to threading messages by subject' preference

 help/C/mail-sorting-message-list.page |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/help/C/mail-sorting-message-list.page b/help/C/mail-sorting-message-list.page
index a227fe9..af994aa 100644
--- a/help/C/mail-sorting-message-list.page
+++ b/help/C/mail-sorting-message-list.page
@@ -7,7 +7,7 @@
     <link type="guide" xref="mail-organizing"/>
     <link type="guide" xref="mail-layout-changing"/>
 
-    <revision pkgversion="3.25.90" version="0.8" date="2017-07-28" status="final"/>
+    <revision pkgversion="3.26.0" version="0.9" date="2017-09-11" status="final"/>
     <credit type="author">
       <name its:translate="no">Andre Klapper</name>
       <email its:translate="no">ak-47 gmx net</email>
@@ -33,7 +33,7 @@
 <title>Sorting Mail in Email Threads</title>
 <p>You can use a threaded message view to sort emails. To enable this feature, click on 
<guiseq><gui>View</gui><gui>Group By Threads</gui></guiseq> or press 
<keyseq><key>Ctrl</key><key>T</key></keyseq>.</p>
 <p>This feature, when enabled, groups replies with the original email and allows you to follow the flow of 
the conversation from one message to the next.</p>
-<note style="tip"><p><app>Evolution</app> recognizes <code its:translate="no" its:locNote="Translators: Do 
NOT translate 'References'">References</code> and <code its:translate="no" its:locNote="Translators: Do NOT 
translate 'In-Reply-To'">In-Reply-To</code> mail headers.</p></note>
+<note style="tip"><p><app>Evolution</app> recognizes <code its:translate="no" its:locNote="Translators: Do 
NOT translate 'References'">References</code> and <code its:translate="no" its:locNote="Translators: Do NOT 
translate 'In-Reply-To'">In-Reply-To</code> mail headers. In addition, you can enable you can enable 
<guiseq><gui>Edit</gui><gui>Preferences</gui><gui>Mail Preferences</gui><gui>General</gui><gui>Message 
Display</gui><gui>Fall back to threading messages by subject</gui></guiseq>.</p></note>
 <p>When a new message arrives, it will be added below the parent message. Threads are sorted and displayed 
based on the date of the most recent message received.</p>
 <note style="tip"><p>For Advanced Users: There is a GSettings key that allows you to toggle between the 
collapsed and expanded state of the email threads. The collapsed state is enabled by default. It can be 
changed by starting the <app>Terminal</app> application and running the command <cmd>gsettings set 
org.gnome.evolution.mail thread-expand true</cmd></p>
 <list>