Fix Zoom Duration on Tap

A simple missing negate sign never captured the key up event for
zooming, which resulted in too long zoom on tap times.

Change-Id: I842835bd790098530fb0f9747f1b95836fcba498
diff --git a/ui/src/frontend/pan_and_zoom_handler.ts b/ui/src/frontend/pan_and_zoom_handler.ts
index dea44c9..bf0738c 100644
--- a/ui/src/frontend/pan_and_zoom_handler.ts
+++ b/ui/src/frontend/pan_and_zoom_handler.ts
@@ -153,7 +153,7 @@
       clearTimeout(tapCancelTimeout);
     };
     this.boundOnZoomKeyUp = e => {
-      if (ZOOM_KEYS.includes(e.key)) {
+      if (!ZOOM_KEYS.includes(e.key)) {
         return;
       }
       const cancellingZoomIn = ZOOM_IN_KEYS.includes(e.key);