Add workaround for bug in qvm-sync-appmenus

qvm-sync-appmenus did not regenerated appmenus for the template itself,
only dependent VMs. Do it manually here. When used with fixed
qvm-sync-appmenus this will regenerate the appmenus twice, which should
be harmless.

This commit should be reverted when new qvm-sync-appmenus got released
and appropriate Require line added here.

templates.spec

@@ -111,6 +111,8 @@ else
     chgrp -R qubes %{dest_dir}
     chmod g+rwX -R %{dest_dir}
 fi
+/usr/libexec/qubes-appmenus/create-apps-for-appvm.sh %{dest_dir}/apps.templates %{template_name} vm-templates
+exit 0
 
 %preun
 if [ "$1" = 0 ] ; then