v.io/jiri: switch cl mail to multipart mode by default.

MultiPart: 2/2
Change-Id: Id859cac12e83fa6bb8d3b4d826d64d90526b5454
diff --git a/jiridoc/doc.go b/jiridoc/doc.go
index 2b056a3..3d95d27 100644
--- a/jiridoc/doc.go
+++ b/jiridoc/doc.go
@@ -119,7 +119,7 @@
  -commit-message-body-file=
    file containing the body of the CL description, that is, text without a
    ChangeID, MultiPart etc.
- -current-project-only=true
+ -current-project-only=false
    Run mail in the current project only.
  -d=false
    Send a draft changelist.