The help document of qemu-nbd misses an option

Host environment

• Operating system: Ubuntu 20.04
• OS/kernel version: Linux tca 5.15.0-46-generic #49~20.04.1-Ubuntu SMP Thu Aug 4 19:15:44 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
• Architecture: x86
• QEMU flavor: qemu-nbd
• QEMU version: version 7.1.50 (v7.1.0-524-gdbc4f48b)
• QEMU command line:

  ./qemu-nbd --help

Description of problem

The "--help" option of qemu-nbd misses the option "tls-hostname".

Steps to reproduce

1. For the option "tls-hostname", the following code appears during option parsing and modifies the tlshostname in qemu-nbd.c:760-762.

        case QEMU_NBD_OPT_TLSHOSTNAME:
            tlshostname = optarg;
            break;

Additional information

But it does not appear in the document provided by "--help".

It may prevent users from using the relevant function.