SVN-Tagging where the SCM data comes from a ProxySCM fails with class-cast
exception of "cannot cast ProxySCM to SubversionSCM"

• Create a Job with SVN SCM
• Create a second Job that inherits the SCM settings via the "use SCM from
  another project" method
• Activate tagging in the second build
• Start and watch it fail.

• Put the same credentials from the first job directly into the second and watch
  it work.

Fixing this bug would save me some settings duplication and additional maintenance.

Thanks to whoever gives this some work