Before 4.X TO 4.2 upgrade manually clean up /var/cache/cloudstack

docs/en-US/Release_Notes.xml

@@ -569,6 +569,10 @@ under the License.
         procedure, and working through it on a test system before working on a production
         system.</para>
       <orderedlist>
+        <listitem>
+          <!-- CLOUDSTACK-4509 -->
+          <para>Manually clean up <filename>/var/cache/cloudstack</filename>.</para>
+        </listitem>
         <listitem>
           <para>Most users of &PRODUCT; manage the installation and upgrades of &PRODUCT; with one
             of Linux's predominant package systems, RPM or APT. This guide assumes you'll be using