[Nmh-workers] scan and mhshow Differ on Setting cur.

[Ralph Corderoy]

Hi,

On this old nmh, if cur is 42 and I `show 314' then running a command
from within less, e.g. `scan .', has 314 be cur.  Good.  Do similar with
mhshow and 42 is still cur.  On exiting mhshow, 314 is cur.

I think the inconsistency trains one to err, e.g. `!rmm', and cur should
be set early on, before the user has a chance to do more.

Cheers, Ralph.