revert: refactor(client): remove extra handling for router base

This reverts commit 299511d.

Author: meteorlxy

packages/@vuepress/client/src/app.ts

@@ -2,6 +2,7 @@ import { computed, h } from 'vue'
 import type { CreateAppFunction, App, ComponentOptions } from 'vue'
 import { createRouter, RouterView, START_LOCATION } from 'vue-router'
 import type { Router, RouterHistory } from 'vue-router'
+import { removeEndingSlash } from '@vuepress/shared'
 import { clientAppEnhances } from '@internal/clientAppEnhances'
 import { clientAppRootComponents } from '@internal/clientAppRootComponents'
 import { clientAppSetups } from '@internal/clientAppSetups'
@@ -71,7 +72,8 @@ export const createVueApp = async ({
 
   // create vue-router
   const router = createRouter({
-    history: historyCreator(siteData.value.base),
+    // TODO: it might be an issue of vue-router that have to remove the ending slash
+    history: historyCreator(removeEndingSlash(siteData.value.base)),
     routes: pagesRoutes,
     scrollBehavior: (to, from, savedPosition) => {
       if (savedPosition) {