Maximum Archive Depth documentation (don't set it to -1)

[Daniel Kleinsinger]

I followed the "conversation" between Julian and Richard Lynch regarding
not allowing password protected zips, but also not checking zips with
the filename rules (the setup I'm aiming for).  It was mentioned that
setting the Maximum Archive Depth to 0 or -1 would disable the filename
checks, but still block password protected zips.   Ummm, don't set it to
-1.  That caused all mail to be rejected as dangerous content (and set
off a nasty loop because of the admin notification emails also getting
rejected).  0 seems to work as designed.

Perhaps the comments in MailScanner.conf could be updated to reflect
this configuration option so that people know what to do.
# The maximum depth to which zip archives will be unpacked, to allow for
# checking filenames and filetypes within zip archives.
# To disable this feature set this to 0.
Maximum Archive Depth = 0

Daniel