start-jupyter: ask if new host keys should be accepted

start-jupyter

@@ -293,7 +293,7 @@ function open_tunnel () {
                "${SJ_USERNAME}@${node}"; then
             echo "Please consider updating your local ssh client!"
             ssh -o ForwardX11=no \
-                -o StrictHostKeyChecking=no \
+                -o StrictHostKeyChecking=ask \
                 -o ProxyCommand="ssh ${SJ_USERNAME}@${SJ_FRONTEND_HOST} nc ${node} 22" \
                 -L "${port}:localhost:${port}" \
                 -Nf \