ssh: T2321: fix invalid string/list assignment of default port
ssh: T2321: fix invalid string/list assignment of default port

Commit 5deb12c509be ("ssh: T2321: add VRF support") restructured the Port
assignment (cleanup from the early days) but it accesses a string with methods
used for a list, resulting in the funny default port 2.

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x