[JENKINS-17058] Add Alexander Fisher's patches from comments.

Updates BapSshHostConfiguration and BapSshPublisherPlugin$Descriptor to override readResolve.

https://issues.jenkins-ci.org/browse/JENKINS-17058?focusedCommentId=177125&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-177125