latency.js: disable the test select while loading results

site-publishing/assets/latency.js

@@ -119,6 +119,9 @@ function pw_test_latency_fetch(project, tests_target, plot_target, weeks, defaul
     pw_plot_target = plot_target;
     set_url_parameter('project', pw_project_cur);
 
+    // Prevent setting the tests while loading the results
+    document.getElementById(tests_target).disabled = true;
+
     let date = new Date();
     date.setHours(0, 0, 0, 0)
     let since = new Date(date.getTime() - (7 * 24 * 60 * 60 * 1000));