Use will-finish-launching event to set open-url event listener

src/main.js

@@ -356,6 +356,7 @@ function setDeeplinkingUrl(url) {
   }
 }
 
+app.on('will-finish-launching', () => {
   // Protocol handler for osx
   app.on('open-url', (event, url) => {
     event.preventDefault();
@@ -365,6 +366,7 @@ app.on('open-url', (event, url) => {
       mainWindow.show();
     }
   });
+});
 
 // This method will be called when Electron has finished
 // initialization and is ready to create browser windows.