http://archivemail.svn.sourceforge.net/viewvc/archivemail?view=rev&revision=266
Fixed crash when archiving an empty maildir with python 2.5.  
The incompatible changes in mailbox.Maildir triggered an assertion in
_archive_dir(); removing that assertion since it looks not useful anyway.

--- trunk/archivemail	2008/03/15 15:59:05	265
+++ trunk/archivemail	2008/03/15 18:42:56	266
@@ -1287,7 +1287,6 @@
         original = mailbox.MHMailbox(mailbox_name)
     else:
         unexpected_error("unknown type: %s" % type)        
-    assert(original)
 
     cache = IdentityCache(mailbox_name)