[web] Replace date library moments.js with luxon

web-src/src/App.vue

@@ -33,7 +33,6 @@ import ModalDialogUpdate from '@/components/ModalDialogUpdate.vue'
 import webapi from '@/webapi'
 import * as types from '@/store/mutation_types'
 import ReconnectingWebSocket from 'reconnectingwebsocket'
-import moment from 'moment'
 
 export default {
   name: 'App',
@@ -90,7 +89,6 @@ export default {
   },
 
   created: function () {
-    moment.locale(navigator.language)
     this.connect()
 
     //  Start the progress bar on app start