First quick check if lastEmittedState and appState are different

Resolves #10195

Auditors: @bridiver @bbondy

Test Plan:
- open two windows
- add bookmark in one
- bookmark should appear in both bookmark toolbars

js/stores/appStore.js

@@ -270,7 +270,7 @@ class AppStore extends EventEmitter {
   }
 
   emitChanges (emitFullState) {
-    if (lastEmittedState) {
+    if (lastEmittedState && lastEmittedState !== appState) {
       const d = diff(lastEmittedState, appState)
       if (!d.isEmpty()) {
         BrowserWindow.getAllWindows().forEach((wnd) => {