wireproto: only expose "between" to version 1 of wire protocols

We recently marked other legacy commands as only available to version 1
of the wire protocols. We held off marking "between" because it is
used as part of the SSH handshake.

Since SSH servers assume they are version 1 by default and the
"between" request that is issued as part of the version 2 handshake
is swallowed and not operated on, everything should "just work" if
"between" is not available to version 2.

Differential Revision: https://phab.mercurial-scm.org/D2513

mercurial/wireproto.py

@@ -740,9 +740,7 b' def batch(repo, proto, cmds, others):'
 
     return bytesresponse(';'.join(res))
 
-# TODO mark as version 1 transport only once interaction with
-# SSH handshake mechanism is figured out.
-@wireprotocommand('between', 'pairs')
+@wireprotocommand('between', 'pairs', transportpolicy=POLICY_V1_ONLY)
 def between(repo, proto, pairs):
     pairs = [decodelist(p, '-') for p in pairs.split(" ")]
     r = []