Fix missing tutorial steps in the funnel logging

The funnel logging code logged a 'virtual' tutorial step whenever
someone started the wizard and skipped that step, but did not do
that when someone restarted it (by clicking "upload more files" on
the thanks screen).

Change-Id: Ibf4970c1c9d5ebcdf34042f368fa1e19be21dec2
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/862