Add missing iteritems() call to the for loop in mailbox.MH.get_message().

Fixes issue2625.
diff --git a/Misc/NEWS b/Misc/NEWS
index 7de7b8a..196f5a9 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -202,6 +202,9 @@
 Library
 -------
 
+- Issue 2625: added missing iteritems() call to the for loop in
+  mailbox.MH.get_message().
+
 - Issue 5585: Add the ability to call an initializer to mulitiprocessing.manager
   so that users can install custonm handlers/etc.