rbd: Reject -blockdev server.*.{numeric, to, ipv4, ipv6}

rbd: Reject -blockdev server.*.{numeric, to, ipv4, ipv6}

We use InetSocketAddress in the QAPI schema.  However, the code
doesn't use inet_connect_saddr(), but formats "host" and "port" into a
configuration string for rados_conf_set().  Thus, members "numeric",
"to", "ipv4" and "ipv6" are silently ignored.  Not nice.  Example:

    -blockdev rbd,node-name=nn,pool=p,image=i,server.0.host=h0,server.0.port=12345,server.0.ipv4=off

Factor a suitable InetSocketAddressBase out of InetSocketAddress, and
use that.  "numeric", "to", "ipv4" and "ipv6" are now rejected.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1490691368-32099-2-git-send-email-armbru@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>