Fix extra http://

Change-Id: Ib1f04b5c0310890bf75bf89c54a87f71342af2e0

BUG=1434
TEST=Tested with factory.

Review URL: http://codereview.chromium.org/3785009
diff --git a/autoupdate.py b/autoupdate.py
index fae2a71..b432b91 100644
--- a/autoupdate.py
+++ b/autoupdate.py
@@ -430,7 +430,7 @@
     if filename is None:
       _LogMessage('unable to find image for board %s' % board_id)
       return self.GetNoUpdatePayload()
-    url = 'http://%s/static/%s' % (self.hostname, filename)
+    url = '%s/static/%s' % (self.hostname, filename)
     _LogMessage('returning update payload ' + url)
     # Factory install is using memento updater which is using the sha-1 hash so
     # setting sha-256 to an empty string.