SUBCOMMAND aliases doubled when help information printed

[rjc]

Currently, three SUBCOMMANDS have aliases and all the aliases are doubled when help information is printed:

$ rbw -h | grep aliases
generate      Generate a new password [aliases: gen, gen]
list          List all entries in the local Bitwarden database [aliases: ls, ls]
remove        Remove a given entry [aliases: rm, rm]

Also, if there's only one, it should obviously read alias.

[rjc]

Ping.

[doy]

this is TeXitoi/structopt#418 - it's not clear that there's a good fix for this on my end other than getting it fixed upstream.

[doy]

fixed in 52efb7f