v.io/jiri: disable multipart CLs by default.

MultiPart: 2/2
Change-Id: I2ec4a3ce826373b9028c392b748c39d79e787804
diff --git a/jiridoc/doc.go b/jiridoc/doc.go
index a9edc7f..4474741 100644
--- a/jiridoc/doc.go
+++ b/jiridoc/doc.go
@@ -120,7 +120,7 @@
  -commit-message-body-file=
    file containing the body of the CL description, that is, text without a
    ChangeID, MultiPart etc.
- -current-project-only=false
+ -current-project-only=true
    Run mail in the current project only.
  -d=false
    Send a draft changelist.