RecordsWidget: don't clear inputs that don't actually have combogrid lookup widgets attached
RecordsWidget: don't clear inputs that don't actually have combogrid lookup widgets attached

anneline/Bika-LIMS,labsanmartin/Bika-LIMS,anneline/Bika-LIMS,rockfruit/bika.lims,labsanmartin/Bika-LIMS,DeBortoliWines/Bika-LIMS,DeBortoliWines/Bika-LIMS,veroc/Bika-LIMS,anneline/Bika-LIMS,veroc/Bika-LIMS,veroc/Bika-LIMS,DeBortoliWines/Bika-LIMS,rockfruit/bika.lims,labsanmartin/Bika-LIMS