fix for #75372. can't drop messages into attachment pane (in compose window.)

a while back, the flavor for messenger dnd changed but this file
was left behind.

this fix makes it so you can dnd messages into the attachment pane, but
until #72617 is fixed, you are also able to drop folders,
which is a bug, see #102630

r=naving, sr=bienvenu


git-svn-id: svn://10.0.0.236/trunk@104369 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/mailnews/compose/resources/content/MsgComposeCommands.js

@@ -2256,7 +2256,7 @@ var attachmentBucketObserver = {
       var rawData = aData.data;
       switch (aData.flavour.contentType) {
       case "text/x-moz-url":
-      case "text/nsmessage":
+      case "text/nsmessageOrFolder":
         var separator = rawData.indexOf("\n");
         if (separator != -1) {
           prettyName = rawData.substr(separator+1);
@@ -2299,7 +2299,7 @@ var attachmentBucketObserver = {
     {
       var flavourSet = new FlavourSet();
       flavourSet.appendFlavour("text/x-moz-url");
-      flavourSet.appendFlavour("text/nsmessage");
+      flavourSet.appendFlavour("text/nsmessageOrFolder");
       flavourSet.appendFlavour("application/x-moz-file", "nsIFile");
       return flavourSet;
     }