Restore previous behaviour and do not request a forward tunnel on
insecure migrations.
For the migrations of all kind this has no direct impact, they all
worked, but an port to much requested from an limited pool is still
not ideal. Also an open tunnel, if not needed.
This is a light regression introduced from commit 1c9d54b.
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>