Clear SR introduced_by field on VM recovery.
Clear SR introduced_by field on VM recovery.

If an SR introduced by a DR task turns out to be needed for VMs which
are being recovered, it should have its introduced_by field set to
Ref.null so that it is not forgotten when the DR task is destroyed.

Signed-off-by: John Else <37b74501daa612e48fea94f9846ed4ddeb6a8f07@citrix.com>

djs55/xcp-networkd,simonjbeaumont/xcp-rrdd,djs55/squeezed,djs55/xcp-rrdd,sharady/xcp-networkd,koushikcgit/xcp-networkd,johnelse/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/xcp-rrdd,robhoes/squeezed,koushikcgit/xcp-networkd,sharady/xcp-networkd,koushikcgit/xcp-rrdd,johnelse/xcp-rrdd,simonjbeaumont/xcp-rrdd,djs55/xcp-networkd,koushikcgit/xcp-rrdd