All templates in the staff client now load the DataTables jquery plugin
through a single include file, datatables.inc, which points to a copy of
the plugin in intranet-tmpl/lib/jquery/plugins. This patch removes the
unused copy of the plugin found in intranet-tmpl/prog/en/lib/jquery/plugins.
To test, search the Koha source for references to
jquery.dataTables.min.js. There should be no files which point to the
redundant file.