Remove short name, so it doesn't conflict with the verbose short name.

[fnando]

What

Remove short flag due to a conflict introduced by #1510.

Why

$ stellar network container start
thread 'main' panicked at /Users/fnando/.cargo/registry/src/index.crates.io-6f17d22bba15001f/clap_builder-4.5.8/src/builder/debug_asserts.rs:112:17:
Command start: Short option names must be unique for each argument, but '-v' is in use by both 'protocol_version' and 'verbose'
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Known limitations

N/A

[leighmcculloch]

Needs help updated otherwise lgtm.