There and back again. We don't actually need the preferred phase at
the time of encountering the WELPI request. [at]joakim-hove was
right, the preferred phase of an injector must reflect the state at
the same report step as the WELPI keyword. In other words, if the
injected phase is reset at the same report step as a WELPI keyword,
then the new preferred phase must be that of the new injected phase.
This reverts commit 3eef45e87d.
6f124fb478