#14380: Have MIMEText defaults to utf-8 when passed non-ASCII unicode

Previously it would just accept the unicode, which would wind up as unicode in
the transfer-encoded message object, which is just wrong.

Patch by Jeff Knupp.
diff --git a/Misc/ACKS b/Misc/ACKS
index 9ed148e..4e6597d 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -548,6 +548,7 @@
 Kim Knapp
 Lenny Kneler
 Pat Knight
+Jeff Knupp
 Greg Kochanski
 Damon Kohler
 Marko Kohtala