Fixed _find_nearest_node_ndarray for dx != dy.
Fixed _find_nearest_node_ndarray for dx != dy.

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