Remove "Minimize to system tray" help page

Four years after GNOME 3.0, this is not a common question anymore
on mailing list / bugtracker / IRC, plus it has never been
something application-specific anyway.

help/C/minimize-to-system-tray.page

@@ -1,31 +0,0 @@
-<page xmlns="http://projectmallard.org/1.0/" xmlns:its="http://www.w3.org/2005/11/its"
-      type="topic" id="minimize-to-system-tray">
-
-  <info>
-    <desc>On minimizing Evolution to the notification area.</desc>
-    
-    <link type="guide" xref="index#common-other-problems" />
-
-    <revision pkgversion="3.5.4" version="0.4" date="2012-07-08" status="final"/>
-    <credit type="author">
-      <name its:translate="no">April Gonzales</name>
-      <email its:translate="no">loonycookie@gmail.com</email>
-    </credit>
-    <credit type="author">
-      <name its:translate="no">Andre Klapper</name>
-      <email its:translate="no">ak-47@gmx.net</email>
-    </credit>
-    
-    <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>
-    
-
-  </info>
-
-
-<title>Minimizing Evolution to the system tray</title>
-
-<p>GNOME, by default, has a <link xref="mail-received-notification">notification area</link> which includes an applet that informs users of any system updates, changes, or events. This includes the arrival of email messages on Evolution. You can refer to this built-in feature of GNOME for any email notifications.</p>
-
-<p>In GNOME version 2 you may modify the notification area and set it up to become a system tray by using external applications which might be available for installation in the software management tool of your distribution. Available options are for example <link href="http://code.google.com/p/tint2/">Tint2</link>. This is no longer possible in GNOME 3.</p>
-</page>
-

help/Makefile.am

@@ -217,7 +217,6 @@ HELP_FILES = \
 	memos-usage-delete-memo.page \
 	memos-usage-edit-memo.page \
 	memos-usage.page \
-	minimize-to-system-tray.page \
 	offline.page \
 	organizing.page \
 	problems-debug-how-to.page \