Remove SSH cloning support from Geo

The following discussion from !3116 (merged) should be addressed:

• @brodock started a discussion: (+4 comments)

  do we need to keep existing ones with SSH? or can we simply move everyone to HTTP by default?

  If we don't require any additional configuration for the HTTP version to work, and we plan into making HTTP default experience, maybe a good idea to migrate existing users already.

  any concerns @stanhu ?

In %10.2 we are adding HTTPS repo cloning support for Geo. This is being done with the understanding that SSH support will be removed in the future.

We need to decide whether to do that at all - do any of our customers rely on SSH cloning and are unable to switch to HTTPS?

One possibility is that some customers may use HTTP (not HTTPS) + SSH. In this case, removing SSH sync would reduce the total security of their installation.

We really need to hear from customers on this though, I think - or at least, make the removal easy to revert!

Current plan is to remove SSH support in %10.3

/cc @jramsay