fix typo

src/views/layout/Navbar.vue

@@ -13,7 +13,7 @@
                         Home
                     </el-dropdown-item>
                 </router-link>
-                <el-dropdown-item divided><span @click="logout" style="display:block;">退出登录</span></el-dropdown-item>
+                <el-dropdown-item divided><span @click="logout" style="display:block;">LogOut</span></el-dropdown-item>
             </el-dropdown-menu>
         </el-dropdown>
     </el-menu>