executable mailbox file modes

[Bob Proulx]

While removing a couple of spams from last night from the mailbox
archive I see that on the new lists1p that the mailbox archives are
all executable.  That's probably just some simple typo somewhere.

  mharc@lists1p:~$ ls -l ~-/2020-01
  -rwxr-xr-x 1 mharc mharc 3896 Jan 14 12:03 
/arc/mharc-mbox/savannah-hackers-public/2020-01

And the same for all of the other mailboxes.  Any idea where that
would have gone wonky?

Bob