Waterfall connector.line.color not in _fullData

[nicolaskruchten]

The reason there's no connector-line-color widget appearing in the RCE is that that attr isn't getting coerced (or something!) and hence not appearing in _fullData:

[etpinard]

@archmoj do all connectors have the same default line color?

[etpinard]

If so, turning

plotly.js/src/traces/waterfall/attributes.js

Line 97 in 424c686

color: lineAttrs.color,

into

line: extendFlat({}, lineAttr.color, {dflt: Color.defaultLine},

should do the trick.