Bug 15674: Make "Column visibility" translatable

The "Column visibility" text button was not translatable, now it is.

Test plan:
1/ Update the template for a given language and translate the "Column
visibility" string
2/ Go on admin/currency.pl
=> The string should be translated.

Signed-off-by: Aleisha <aleishaamohia@hotmail.com>

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>

Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com

koha-tmpl/intranet-tmpl/prog/en/includes/columns_settings.inc

@@ -26,6 +26,7 @@ function KohaTable(selector, dt_parameters, columns_settings) {
         {
             extend: 'colvis',
             columns: included_ids,
+            text: _('Column visibility'),
         }
     ];
     var table = $(selector).dataTable($.extend(true, {}, dataTablesDefaults, dt_parameters));