Fix example box_game_spectator.rs

[AgustinRamiroDiaz]

I was getting an error due to conflicting flags, since -h is reserved as the short for --help, it can't be used as the short for host

> cargo run --example box_gam
e_spectator -- --local-port 7002 --num-players 2 --host 127
.0.0.1:7000
   Compiling bevy_ggrs v0.14.0 (/home/az/dev/bevy_ggrs)
    Finished dev [unoptimized + debuginfo] target(s) in 15.43s
     Running `target/debug/examples/box_game_spectator --local-port 7002 --num-players 2 --host '127.0.0.1:7000'`
thread 'main' panicked at /home/az/.cargo/registry/src/index.crates.io-6f17d22bba15001f/clap_builder-4.4.18/src/builder/debug_asserts.rs:112:17:
Command bevy_ggrs: Short option names must be unique for each argument, but '-h' is in use by both 'host' and 'help' (call `cmd.disable_help_flag(true)` to remove the auto-generated `--help`)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[johanhelsing]

Makes sense to me, thanks!