lxd/cluster/heartbeat: Immediately ping remaining members when ctx is cancelled in APIHeartbeat.Send
lxd/cluster/heartbeat: Immediately ping remaining members when ctx is cancelled in APIHeartbeat.Send

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

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