sync: Update default -j flag from manifest

If the manifest is updated and the default sync-j attribute
was modified, honor it during this sync session if the user
has not supplied a -j flag on the command line.

Change-Id: I127ee5c779e2bbbb40b30bddc10ec1fa704b3bf3
Signed-off-by: Shawn O. Pearce <sop@google.com>

subcmds/sync.py

diff --git a/subcmds/sync.py b/subcmds/sync.py
index 7ab0b1f..244a560 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -136,7 +136,6 @@
                  help='be more quiet')
     p.add_option('-j','--jobs',
                  dest='jobs', action='store', type='int',
-                 default=self.jobs,
                  help="projects to fetch simultaneously (default %d)" % self.jobs)
     if show_smart:
       p.add_option('-s', '--smart-sync',
@@ -401,6 +400,8 @@
       if not syncbuf.Finish():
         sys.exit(1)
       self.manifest._Unload()
+      if opt.jobs is None:
+        self.jobs = self.manifest.default.sync_j
     all = self.GetProjects(args, missing_ok=True)
 
     if not opt.local_only: