web/origin-manager: paginate request history.

Otherwise, packages that are frequently updated (such as
openSUSE-release-tools) overflow the page with so many request entries.

web/origin-manager/main.js

@@ -240,6 +240,8 @@ function history_table_init(selector) {
         initialSort: [
             { column: 'request', dir: 'desc' },
         ],
+        pagination: 'local',
+        paginationSize: 15,
         rowClick: history_select_hash,
         selectable: 1,
         tooltips: true,