Change MIN_GHOST_GENERIC_DELTA to match measure definition
Change MIN_GHOST_GENERIC_DELTA to match measure definition

Fixes #1646
annapowellsmith/openpresc,ebmdatalab/openprescribing,ebmdatalab/openprescribing,annapowellsmith/openpresc,ebmdatalab/openprescribing,ebmdatalab/openprescribing,annapowellsmith/openpresc,annapowellsmith/openpresc