Change the version command line arg from `-v` to `-version`.
Change the version command line arg from `-v` to `-version`.

For consistency with the rest of the arguments.

thomasf/obfs4,getlantern/obfs4,ktcunreal/obfs4,PeterCxy/obfs4,csersoft/obfs4,afdnlw/obfs4,bingyuxq/obfs4