fix incoming_node for hex normal fault
fix incoming_node for hex normal fault

RondaStrauch/landlab,landlab/landlab,amandersillinois/landlab,Carralex/landlab,SiccarPoint/landlab,csherwood-usgs/landlab,ManuSchmi88/landlab,cmshobe/landlab,ManuSchmi88/landlab,Carralex/landlab,cmshobe/landlab,landlab/landlab,amandersillinois/landlab,SiccarPoint/landlab,Carralex/landlab,RondaStrauch/landlab,laijingtao/landlab,cmshobe/landlab,RondaStrauch/landlab,ManuSchmi88/landlab,laijingtao/landlab,landlab/landlab,csherwood-usgs/landlab