Fix: W3C errors or warnings

htdocs/admin/tools/dolibarr_export.php

htdocs/core/tpl/freeproductline_edit.tpl.php

htdocs/core/tpl/predefinedproductline_edit.tpl.php

htdocs/ftp/admin/ftpclient.php

htdocs/install/fileconf.php

htdocs/product/canvas/default/tpl/create.tpl.php

htdocs/societe/canvas/default/tpl/card_create.tpl.php

htdocs/societe/canvas/default/tpl/card_edit.tpl.php

htdocs/societe/canvas/individual/tpl/card_create.tpl.php

htdocs/societe/canvas/individual/tpl/card_edit.tpl.php