Uploading a zip file with the unpack option fails results in a crash

## Problem description
When uploading a zip file in the web UI, the server crashes with a segfault

```
May 02 15:15:24 rottnest systemd-coredump[585793]: [🡕] Process 585354 (java) of user 952 dumped core.

Stack trace of thread 585456:
#0 0x00007f3b2ff86c2b fchown (libc.so.6 + 0xf7c2b)
#1 0x00007f3b2fca2799 Java_sun_nio_fs_UnixNativeDispatcher_fchown0 (libnio.so + 0xd799)
#2 0x00007f3b17d58728 n/a (n/a + 0x0)
#3 0x00007f3b17d543aa n/a (n/a + 0x0)
#4 0x00007f3b17d543aa n/a (n/a + 0x0)
#5 0x00007f3b17d543aa n/a (n/a + 0x0)
#6 0x00007f3b17d543aa n/a (n/a + 0x0)
#7 0x00007f3b17d543aa n/a (n/a + 0x0)
#8 0x00007f3b17d54503 n/a (n/a + 0x0)
#9 0x00007f3b17d543aa n/a (n/a + 0x0)
#10 0x00007f3b17d543aa n/a (n/a + 0x0)
#11 0x00007f3b17d543aa n/a (n/a + 0x0)
#12 0x00007f3b17d547fa n/a (n/a + 0x0)
#13 0x00007f3b17d54503 n/a (n/a + 0x0)
#14 0x00007f3b17d54503 n/a (n/a + 0x0)
#15 0x00007f3b18805afc n/a (n/a + 0x0)
ELF object binary architecture: AMD x86-64
```

### Steps to reproduce

1. Enable uploads
2. Create a zip file containing music files
3. Upload the zip file in the web UI, including checking the "Automatically unpack ZIP-file." option
4. Notice that although the upload completes, the unpacking fails, and the server crashes.

## System information

* **Airsonic version**: 11.0.0-SNAPSHOT.20230409010214 – April 9, 2023, 11:02:14 AM AEST [Commit: [9b43fa47566aa37a3aacdf2255cf9c97cd3b0bd9](https://github.com/airsonic-advanced/airsonic-advanced/commit/9b43fa47566aa37a3aacdf2255cf9c97cd3b0bd9)] - installed via https://aur.archlinux.org/packages/airsonic-advanced-git
* **Operating system**: Arch Linux
* **Java version**: openjdk 20.0.1 2023-04-18
* **Proxy server**: nginx
* **Client**: Firefox on Linux
* **Language**: English

## Additional notes

I can see that the segfault happens in a `fchown` syscall:
* Why would this be necessary during the unpacking process?
* Is there an assumption about file system permissions that is not being met? I've set the upload directory with permissions 777 and owned by the same user/group as the airsonic-advanced service.
* Does systemd prevent it from working somehow?