fix histogram aggregation in case of non-numeric position axis
fix histogram aggregation in case of non-numeric position axis

asolagmbh/plotly.js,aburato/plotly.js,plotly/plotly.js,iongroup/plotly.js,iongroup/plotly.js,asolagmbh/plotly.js,etpinard/plotly.js,plotly/plotly.js,etpinard/plotly.js,iongroup/plotly.js,asolagmbh/plotly.js,plotly/plotly.js,aburato/plotly.js,plotly/plotly.js,etpinard/plotly.js