When deploying with subversion, we get asked for authentication. If you want to skip this message, jenkins says you can adjust '/var/lib/hudson/.subversion/servers', but that file does not exists.

That should be: '/var/lib/jenkins/.subversion/servers'

A temporary fix is to create the file '/var/lib/hudson/.subversion/servers' and put settings there, otherwise jenkins skips the changes you make to '/var/lib/jenkins/.subversion/servers'

ORIGINAL MESSAGE:

ATTENTION! Your password for authentication realm:

Subversion repos

can only be stored to disk unencrypted! You are advised to configure
your system so that Subversion can store passwords encrypted, if
possible. See the documentation for details.

You can avoid future appearances of this warning by setting the value
of the 'store-plaintext-passwords' option to either 'yes' or 'no' in
'/var/lib/hudson/.subversion/servers'.