Fixing the login page availability

To access the login page you need login.html. Then this page loads the
login.js that generate the login.vue in the div#app (with the '#app')

frontend/src/login.js

@@ -3,4 +3,4 @@ import './assets/main.css'
 import { createApp } from 'vue'
 import App from './Login.vue'
 
-createApp(App).mount('#login')
+createApp(App).mount('#app')