message: util: Add missing unlinkat to syscall sandbox
diff: @@ -600,6 +600,7 @@ public:
  allowed_syscalls.insert(__NR_statfs); // get filesystem statistics
  allowed_syscalls.insert(__NR_statx); // get file status (extended)
  allowed_syscalls.insert(__NR_unlink); // delete a name and possibly the file it refers to
  + allowed_syscalls.insert(__NR_unlinkat); // delete relative to a directory file descriptor
  }
  void AllowFutex()
  