Add validation for SSH Location

Previously missed validation for SSH Location
when configuring kdump with ssh.
Now add it for ssh location.

Change-Id: I7d9153cdd7cddecf238a82d7e1639f74386795fe
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=981576
Signed-off-by: hadong <hadong0720@gmail.com>