show application if not focused

When clicking on the tray icon, if window is not focused show it instead of closing it.
If window is closed or not focused will be shown.

src/app/app.tray.js

@@ -51,7 +51,7 @@ function setupTray(browserWindow) {
 			role: 'quit',
 		},
 	]))
-	tray.on('click', () => browserWindow.show())
+	tray.on('click', () => browserWindow.isFocused() ? browserWindow.close() : browserWindow.show())
 
 	browserWindow.on('close', event => {
 		if (!isAppQuitting) {