ctdb-build: Install pre-built manpages when xsltproc not available

ctdb-build: Install pre-built manpages when xsltproc not available

At the moment they are not installed at all if xsltproc is not
available.

They can still be filtered to have the paths match what was
configured.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Jose A. Rivera <jarrpa@samba.org>
Reviewed-by: Michael Adam <obnox@samba.org>
Autobuild-User(master): Michael Adam <obnox@samba.org>
Autobuild-Date(master): Tue Sep 15 11:57:44 CEST 2015 on sn-devel-104