Status: report actual min protocol version

[itizir]

Hi!
Just a minor thing, but when getting the status of weave, it always reports Protocol: weave 1..2, which isn't particularly useful...

[bboreham]

What does it report after your change?

[itizir]

It would report the min protocol version set in the router, which is relevant when querying weave for its status (https://github.com/weaveworks/weave/blob/master/site/troubleshooting.md).

Would be useful to be able to easily check whether weave has been started with --min-protocol-version=2, which is necessary for security. But as things are, the Protocol printout in the status is hardcoded to 1..2.

I'm also noticing now that the NewRouter function in mesh does not check the set min version is valid (within bounds)... Worth changing that, too?

[bboreham]

Sorry, lost track of this.
Having looked at the code, I think the underlying point is the min version is configurable by user of this library, so we should print out what they configured. So LGTM, thanks!