Re: [PATCH v3 24/35] connect: refactor git_connect to only get the protocol version once

> Instead of having each builtin transport asking for which protocol
> version the user has configured in 'protocol.version' by calling
> `get_protocol_version_config()` multiple times, factor this logic out
> so there is just a single call at the beginning of `git_connect()`.
> 
> This will be helpful in the next patch where we can have centralized
> logic which determines if we need to request a different protocol
> version than what the user has configured.
> 
> Signed-off-by: Brandon Williams <bmwill@google.com>