storage variables in model are incorrect

[noahrhodes]

Redundant variables are added to the problems.

    _PMs.variable_storage(pm)
    _PMs.variable_storage_indicator(pm, relax = true)
    _PMs.variable_storage_mi_on_off(pm)

Likely should be

    _PMs.variable_storage_indicator(pm, relax = true)
    _PMs.variable_storage_mi_on_off(pm)