Port 0 is interpreted, per the spec (but inconsistently among router
software) as requesting to map every single available port on the UPnP
gateway to the internal IP address. We'd previously avoided picking
ports below 1024 for one of the two UPnP methods (in #7457), and this
change moves that logic so that we avoid it in all cases.
Updates #8992
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I20d652c0cd47a24aef27f75c81f78ae53cc3c71e
(cherry picked from commit 77ff705545d63b30c170d8958cd76be764bc8a6b)
Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
bd914d5186