Daniel Beck says that this path /scm/SubversionSCM/enterCredential is obsolete as of the credentials-plugin.
https://github.com/jenkinsci/subversion-plugin/blob/2a14db8c50beeab8ae96f57e8e23176dad58944a/src/main/resources/hudson/scm/SubversionSCM/DescriptorImpl/url-help.properties#L33