[web-src] Consolidate burger menu handling on route change in router/index.js

web-src/src/App.vue

@@ -182,9 +182,6 @@ export default {
   },
 
   watch: {
-    '$route' (to, from) {
-      this.$store.commit(types.SHOW_BURGER_MENU, false)
-    },
     'show_burger_menu' () {
       if (this.show_burger_menu) {
         document.querySelector('html').classList.add('is-clipped')

web-src/src/router/index.js

@@ -247,10 +247,7 @@ export const router = new VueRouter({
 })
 
 router.beforeEach((to, from, next) => {
-  if (store.state.show_burger_menu) {
+  const burgerMenuVisible = store.state.show_burger_menu
   store.commit(types.SHOW_BURGER_MENU, false)
-    next(false)
-  } else {
-    next()
-  }
+  next(!burgerMenuVisible)
 })