Fix has_change_permission invocation.
Fix has_change_permission invocation.

As @gradel pointed out, the optional "object" argument takes a model
instance, not a model.

I'm guessing the reason this hasn't been blowing up with errors is that
the object argument is ignored if the user has change permissions to all
objects in the model.

ryneeverett/mezzanine,readevalprint/mezzanine,sjdines/mezzanine,stephenmcd/mezzanine,sjuxax/mezzanine,molokov/mezzanine,molokov/mezzanine,sjdines/mezzanine,sjdines/mezzanine,jerivas/mezzanine,jerivas/mezzanine,frankier/mezzanine,christianwgd/mezzanine,wbtuomela/mezzanine,dsanders11/mezzanine,molokov/mezzanine,ryneeverett/mezzanine,stephenmcd/mezzanine,readevalprint/mezzanine,stephenmcd/mezzanine,christianwgd/mezzanine,wbtuomela/mezzanine,sjuxax/mezzanine,jerivas/mezzanine,dsanders11/mezzanine,dsanders11/mezzanine,sjuxax/mezzanine,readevalprint/mezzanine,frankier/mezzanine,wbtuomela/mezzanine,christianwgd/mezzanine,ryneeverett/mezzanine,frankier/mezzanine