dns/dnsmasq-devel: 2.87rc1 release candidate

Changes since test9:

+ Tweak DHCPv6 relay code so that packets relayed towards a server

have source address on the server-facing network, not the
client facing network. Thanks to Luis Thomas for spotting this
and initial patch.

(cherry picked from commit fc85d8413735ae7512f9c8526b6fd7946dc908f1)