crimson: use pick_addr() for picking peer addr

crimson: use pick_addr() for picking peer addr

in teuthology tests, there is good chance that we have ceph.conf
containing:

mon host = 172.21.15.122

which is translated to two monitors

- a: 172.21.15.122:3300
- a-legacy: 172.21.15.122:6789

both has protocol type of "any". so, to enable crimson to use settings
like this, we should let crimson to accept them, and drop the connection
if the peer claim to be using an incompatible protocol, when they are
exchanging banners.

Signed-off-by: Kefu Chai <kchai@redhat.com>