MDL-73734 tool_httpreplace: Use streaming output api

admin/tool/httpsreplace/tool.php

@@ -58,6 +58,14 @@ $finder = new \tool_httpsreplace\url_finder();
 $PAGE->set_cacheable(false);
 $progressbar = new progress_bar();
 
+// Preemptively reset the navcache before closing, so it remains the same on shutdown.
+navigation_cache::destroy_volatile_caches();
+\core\session\manager::write_close();
+
+// Prepare for streamed output.
+echo $OUTPUT->footer();
+echo $OUTPUT->select_element_for_append();
+
 if (!$data = $form->get_data()) {
 
     echo $progressbar->create();
@@ -103,4 +111,3 @@ if (!$data = $form->get_data()) {
 
     echo $OUTPUT->continue_button(new moodle_url('/admin/settings.php', ['section' => 'httpsecurity']));
 }
-echo $OUTPUT->footer();