container/lxc: Improves comment on DHCP host config removal
container/lxc: Improves comment on DHCP host config removal

The call to networkUpdateStatic() during container deletion is dependent on a specific ordering that is non-obvious, adds a comment for future readers to avoid introducing this bug again.

Fixes #5889

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

lxc/lxd,atxwebs/lxd,Skarlso/lxd,hallyn/lxd,stgraber/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,atxwebs/lxd,stgraber/lxd,mjeanson/lxd,hallyn/lxd,mjeanson/lxd,Skarlso/lxd,stgraber/lxd,Skarlso/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,atxwebs/lxd,atxwebs/lxd,lxc/lxd,hallyn/lxd,mjeanson/lxd,Skarlso/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd,lxc/lxd