lxd/cluster/heartbeat: Save member state gathered so far if heartbeat is cancelled
lxd/cluster/heartbeat: Save member state gathered so far if heartbeat is cancelled

Avoids wasting the state gathered and keeps the DB up to date as best as possible.

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

stgraber/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,lxc/lxd