Merge PR #25900 into master

Merge PR #25900 into master

* refs/pull/25900/head:
	qa/tasks/ceph.py: bracket addrvecs in mon_host etc
	vstart.sh: bracket addrvec on mon_host for msgr2-only mode
	unittest_addrs: entity_addr_t: strengthen tests slightly
	common/ceph_argparse: make parse_ip_port_vec handle list of addrs or addrvecs
	common/ceph_argparse: parse_ip_port_vec returns addrvecs, not addrds
	msg/msg_types: entity_addrvec_t: require brackets for size >1
	msg/msg_types: entity_addrvec_t: allow brackets when parsing addrvec to match output
	msg/msg_types: entity_addrvec_t: allow only ',' as an addrvec separator
	msg/msg_types: entity_addr_t: we should not parse an addrvec
	msg/msg_types: entity_addr_t: fix empty string parse cases
	msg/msg_types: entity_addr_t: is_ipv6() and is_ipv4()

Reviewed-by: Ricardo Dias <rdias@suse.com>