help message alway show default key map even it's customised

[butterflyfish]

at my vimrc, it have

g:magit_stage_hunk_mapping = '-'

but vimagit help message still use 'S'.

[jreybert]

Nice one! A pull request is more than welcome.

[butterflyfish]

@jreybert , I'm only vim user, and never write vim scripts. Sorry.

[jreybert]

That would be a good, start, update message won't be that hard ;)

Anyway, if you really don't want to do this, I'll do.