Licence for bacula-doc 11.0.0 and later

Hi Eric,

I wanted to update the documentation package for Debian, but I noticed
that the file LICENSE (which said the documentation is licensed under
CC-BY-SA) went missing beginning with the 11.0.0 release of bacula-doc.

Right now the only file about licensing in the docs is in
latex/license.tex:

> This manual and the associated code is the Enterprise version of
> Bacula. It is not open source or licensed under the AGPLv3 as is
> the Bacula community source code. Bacula Enterprise software is
> proprietary.

I suppose that's an oversight, could you fix that?

Regards

Carsten