[Issue] 基本路径非根目录挂载Webdav

[Andres-Peng]

当设置 用户的 基本路径 base_path 不是根目录时，
windows 挂载 webdav,
会发生修改保存文件异常，应该是路径问题。

Version: v3.28.0
WebVersion: 3.28.0
`

用户 基本路径 设为根目录：新建文件，修改保存正常

[GIN] 2023/10/13 - 15:39:30 | 304 | 280.173µs | ::1 | GET "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:35 | 200 | 330.931µs | ::1 | LOCK "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:35 | 401 | 47.181µs | ::1 | HEAD "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:35 | 200 | 187.193µs | ::1 | HEAD "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:35 | 201 | 676.201µs | ::1 | PUT "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:35 | 207 | 524.573µs | ::1 | PROPPATCH "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:35 | 204 | 140.808µs | ::1 | UNLOCK "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:35 | 207 | 459.837µs | ::1 | PROPFIND "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:39:38 | 207 | 794.798µs | ::1 | PROPFIND "/nas/dav"

用户 基本路径 设为/Andres：新建文件，修改保存异常 请求路径是否有问题 /nas/dav/

[GIN] 2023/10/13 - 15:39:45 | 200 | 142.757µs | ::1 | GET "/nas/assets/AddOrEdit.2ab72af9.js"
[GIN] 2023/10/13 - 15:39:45 | 200 | 1.404242ms | ::1 | GET "/nas/api/admin/user/get?id=3"
[GIN] 2023/10/13 - 15:39:47 | 200 | 483.792µs | ::1 | POST "/nas/api/fs/dirs"
[GIN] 2023/10/13 - 15:39:49 | 200 | 11.492788ms | ::1 | POST "/nas/api/admin/user/update"
[GIN] 2023/10/13 - 15:39:49 | 200 | 1.66666ms | ::1 | GET "/nas/api/admin/user/list"
[GIN] 2023/10/13 - 15:39:53 | 207 | 2.038368ms | ::1 | PROPFIND "/nas/dav"
[GIN] 2023/10/13 - 15:39:55 | 200 | 375.227µs | ::1 | GET "/nas/dav/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:02 | 200 | 280.643µs | ::1 | LOCK "/nas/dav/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:02 | 401 | 41.218µs | ::1 | HEAD "/nas/dav/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:02 | 200 | 169.458µs | ::1 | HEAD "/nas/dav/新建文本文档.txt"
[31mERRO [0m[2023-10-13 15:40:02] PUT /nas/dav/新建文本文档.txt webdav: locked
[GIN] 2023/10/13 - 15:40:02 | 412 | 181.254µs | ::1 | PUT "/nas/dav/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:02 | 204 | 95.651µs | ::1 | UNLOCK "/nas/dav/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:02 | 207 | 415.252µs | ::1 | PROPFIND "/nas/dav/新建文本文档.txt"

用户 基本路径 改回为根目录：新建文件，修改保存正常

[GIN] 2023/10/13 - 15:40:09 | 200 | 1.276048ms | ::1 | GET "/nas/api/admin/user/get?id=3"
[GIN] 2023/10/13 - 15:40:16 | 200 | 11.584982ms | ::1 | POST "/nas/api/admin/user/update"
[GIN] 2023/10/13 - 15:40:16 | 200 | 1.960838ms | ::1 | GET "/nas/api/admin/user/list"
[GIN] 2023/10/13 - 15:40:17 | 207 | 1.568753ms | ::1 | PROPFIND "/nas/dav"
[GIN] 2023/10/13 - 15:40:18 | 207 | 321.039µs | ::1 | PROPFIND "/nas/dav/Andres"
[GIN] 2023/10/13 - 15:40:24 | 200 | 193.336µs | ::1 | PROPFIND "/nas/"
[GIN] 2023/10/13 - 15:40:25 | 200 | 360.068µs | ::1 | LOCK "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:25 | 401 | 42.25µs | ::1 | HEAD "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:25 | 200 | 216.859µs | ::1 | HEAD "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:26 | 201 | 701.808µs | ::1 | PUT "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:26 | 207 | 320.57µs | ::1 | PROPPATCH "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:26 | 204 | 103.864µs | ::1 | UNLOCK "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:26 | 207 | 428.241µs | ::1 | PROPFIND "/nas/dav/Andres/新建文本文档.txt"
[GIN] 2023/10/13 - 15:40:27 | 207 | 831.165µs | ::1 | PROPFIND "/nas/dav/Andres/工作"`