fix update error

lib/main-app.js

@@ -44,7 +44,7 @@ const updater = new GhReleases(ghReleasesOpts)
 // Check for updates
 // `status` returns true if there is a new update available
 function checkUpdate () {
-  if (process.platform === 'linux') {
+  if (process.platform === 'linux' || isUpdateReady) {
     return true
   }
   updater.check((err, status) => {
@@ -54,6 +54,7 @@ function checkUpdate () {
       return
     }
     if (status) {
+      mainWindow.webContents.send('update-found', 'Update available!')
       updater.download()
     }
   })
@@ -69,6 +70,7 @@ updater.on('update-downloaded', (info) => {
 ipc.on('update-app-confirm', function (event, msg) {
   console.log('confirmed')
   if (isUpdateReady) {
+    mainWindow.removeAllListeners()
     updater.install()
   }
 })