Remove obsolete reference to migration from KMail to KMail2, which happened back in 2010.

doc/kmail2/intro.docbook

@@ -81,8 +81,7 @@ for details.</para>
 <para>We hope you will enjoy &kmail;!</para>
 <sect2 id="getting-help">
 <title>Getting Help</title>
-<note><para>If you experience any problems migrating to &kmail; 2 please read the chapter <link linkend="troubleshooting">Troubleshooting</link>.
-</para></note>
+ 
 <para>&kmail;'s homepage can be found at <ulink url="https://userbase.kde.org/Special:MyLanguage/KMail">https://userbase.kde.org/KMail</ulink>. There you will
 find useful links (&eg;, to the user and developer mailing lists, and to the community wiki pages.) Please report any bugs in &kmail; using
 <menuchoice><guimenu>Help</guimenu><guimenuitem>Report Bug...</guimenuitem></menuchoice>.</para>