[Bug 779751] Re: admindb fail to find message charset

I made one additional change to the patch. Instead of "mcset = part.get_content_charset('us-ascii')", I do "mcset = part.get_content_charset() or 'us-ascii'" as in Decorate.py to allow for charset= with no value.

** Changed in: mailman Importance: Undecided => Medium

** Changed in: mailman Status: New => Fix Committed

** Changed in: mailman Milestone: None => 2.1.15

** Changed in: mailman Assignee: (unassigned) => Mark Sapiro (msapiro)