docs-xml: fix use of <smbconfoption> tag (fix bug #9345)

docs-xml: fix use of <smbconfoption> tag (fix bug #9345)

Signed-off-by: Björn Baumbach <bb@sernet.de>
Reviewed-by: Karolin Seeger <ks@samba.org>
Autobuild-User(master): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(master): Fri Nov  2 12:37:42 CET 2012 on sn-devel-104
(cherry picked from commit 3ecbe8c83a003825fc58f6dcb9e02a35aad2d86e)

Autobuild-User(v4-0-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-0-test): Mon Nov  5 13:09:12 CET 2012 on sn-devel-104
(cherry picked from commit 6195cb667b1c162436bfbf5d4f499bdc776f83b4)
(cherry picked from commit a6dea8e6556bd5e391cd709b86664fb7cc34433a)
(cherry picked from commit 9a8d7ab3773e1d4d1981f8b45998d689180a4cbf)