pool: Respect LAN port range for internal srmcp transfers

When copying files internally within the same dCache using server side srmCopy,
the actual transfer is done through DCAP. The mover implementing this did not
respect the LAN port range. This patch resolves that problem.

Target: trunk
Request: 2.10
Request: 2.9
Request: 2.8
Request: 2.7
Request: 2.6
Require-notes: yes
Require-book: yes
Acked-by: Karsten Schwank <karsten.schwank@desy.de>
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: https://rb.dcache.org/r/7348/
(cherry picked from commit f7fc29d8eaec1e3a1cd39e3c61e72cf0dfce65bd)
Merge pull request #895 from gbehrmann/fix/2.7/rb7348

pool: Respect LAN port range for internal srmcp transfers