修复 undefined 问题

src/pinia/system-store.ts

@@ -53,9 +53,13 @@ export const useSystemStore = defineStore('system', {
     actions: {
         merge() {
             for (let key in userConfig) {
+                if (typeof this.userConfig === 'undefined') {
+                    this.userConfig = userConfig
+                    return
+                }
                 if (!XEUtils.has(this.userConfig, key)) {
                     // @ts-ignore
-                    this.userConfig[key] = userConfig[key]
+                    this.userConfig[key] = userConfig[key];
                 }
             }
         },