Clear cartesian axis titles when deleting subplots

[etpinard]

Previously,

var newPlotLayout = {
  "xaxis":{ "title":"xAxis Name" },
  "yaxis":{ "title":"yAxis Name" }
}

var traces = [ {
  "type":"scattergl",  // or any other non-cartesian type
  "x":[1,2,3,4,5,6,7],
  "y":[0,5,8,9,8,5,0]
}]

Plotly.newPlot('graph', [], newPlotLayout).then(function(){
  Plotly.addTraces('graph', traces);
})

yielded

After this fix, we get:

as desired.

[alexcjohnson]

Ah, the annoying orphan axes... 💃