fix(html): trigger filter on page load (#1413)

In the HTML report, if the "filter" input contains a value when
the page loads, it is ignored.  This happens even though an event
is actually created on start-up to trigger the refresh.

I believe this is a regression introduced in
9a1954a, when the observed
events changed from "keyup change" to "input".

coverage/htmlfiles/coverage_html.js

@@ -166,7 +166,7 @@ coverage.wire_up_filter = function () {
 
     // Trigger change event on setup, to force filter on page refresh
     // (filter value may still be present).
-    document.getElementById("filter").dispatchEvent(new Event("change"));
+    document.getElementById("filter").dispatchEvent(new Event("input"));
 };
 
 coverage.INDEX_SORT_STORAGE = "COVERAGE_INDEX_SORT_2";