Issue with aggregation when only Y is defined

[dmt0]

To reproduce:

1. Create scatter with Y defined, but not X
2. Try to add an aggregation.

Console error:

factory.js?b9b2:113 
Error while plotting: TypeError: Cannot set property 'type' of undefined
    at Object.plots.supplyTransformDefaults (plotly-with-meta.js?ab3a:128097)
    at Object.plots.supplyTraceDefaults (plotly-with-meta.js?ab3a:128036)
    at Object.plots.supplyDataDefaults (plotly-with-meta.js?ab3a:127800)
    at Object.plots.supplyDefaults (plotly-with-meta.js?ab3a:127265)
    at Object.exports.react (plotly-with-meta.js?ab3a:105509)
    at eval (factory.js?b9b2:100)

Reported to plotly.js: plotly/plotly.js#2908