Format deploy console messages to include http:// protocol

This is a fix to a personal annoyance I have with the `meteor deploy` command. The messages that the `deploy` command prints into the console have the deploy URL without the protocol, so they aren't interpreted as links by the terminal emulator.

This is just a simple fix to add the protocol to the console messages, nothing more.

Before: `Now serving at mue-staging.meteor.com`
After: `Now serving at http://mue-staging.meteor.com` (which gets linked by the terminal emulator)

I'm not sure if the message should use the `http` or `https` protocol, but I decided on `http` because it's less prone to breakage and you can always access the SSL version yourself.