Don't fade the control bar if it has focus

Fixes github issue #1369

kasmweb/app/ui.js

@@ -585,6 +585,13 @@ const UI = {
     },
 
     idleControlbar() {
+        // Don't fade if a child of the control bar has focus
+        if (document.getElementById('noVNC_control_bar')
+                .contains(document.activeElement) && document.hasFocus()) {
+            UI.activateControlbar();
+            return;
+        }
+
         document.getElementById('noVNC_control_bar_anchor')
             .classList.add("noVNC_idle");
     },