Connecting with JSch broken for alpine

[kevin-yee-finix]

Previously able to connect with JSch, after pulling recent version with #307/#308 changes this is not working any longer.

Get this error:

SFTP Connection attempt failed: 
com.jcraft.jsch.JSchException: Algorithm negotiation fail

This was not a problem with earlier alpine releases.
On the sftp side:
no matching host key type found. Their offer: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521 [preauth]

Current workaround: Use alpine 3.7
docker pull atmoz/sftp:alpine-3.7
This is not ideal as older release won't have a lot of features/updates.

[KDGundermann]

having the same problem with alpine 3.16
the sshd server offers only : ssh-ed25519,rsa-sha2-512,rsa-sha2-256

see also (#296)

[ghherlin]

The cause is explained in #335