subtickets - gantt display - suppress red arrow line from "parent" to milestone

[jc]

I'm installing/configuring tracjsgantt - and it's a great Job. I'm refering back to the diagram on the page: ​http://trac-hacks.org/wiki/TracJsGanttPlugin Which Shows collapsible Groups of Tasks - the parent Tasks have black bar on the diagram.

I can get a similar effect with the Subtickets module. The parent of the subtasks must also have the same Milestone - which makes sense, otherwise it is not displayed with the

[[TracJSGanttChart(milestone=testmilestone)]]

directive.

This is fine, the only Thing is that the black line displayed also has a red arrow line leading to the Milestone. Is there a way to not Display this arrow line