Bugfix: bitcoin-cli: Check length of peer.transport_protocol_type

[luke-jr]

"v" would dereference beyond the string length, and "v10" would show as '1'

Turn both of these cases into a blank, like anything else unexpected currently is.

[DrahtBot]

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ACK	sipa, hernanmarino, alfonsoromanz, achow101

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[maflcko]

I don't think supporting a malicious server reply in bitcoin-cli is a use case to support. I think just using .at(1) would be fine as well, presumably resulting in a non-UB crash, similar to when the server replies with the wrong type?

[luke-jr]

Maybe, but this seems cleaner anyway since it also addresses far-future "v10" or such. Any reason to prefer an exception over this?

[sipa]

utACK c3e632b.

I wouldn't call it a bugfix, but it does seem slightly better.

[hernanmarino]

utACK c3e632b

[alfonsoromanz]

ACK c3e632b

[achow101]

ACK c3e632b