Update references migration to reflect production status
phase4 has already been executed.
phase5 still has to be executed, but can not happen before deploying
Ie4d2abb0af83b680640cb46c6c8adbb774488e91 (otherwise we'd drop indices that are
still in use)
Note that 2 of the indices in phase5 (*_tmp) have already been dropped in
officewiki (which is fine, they're unused)