'node' undefined - use 'newNode' instead

There's a small typo in `insertSegment` from `objectFL.RContour`, which raises a `NameError` exception when one tries to insert a segment inside a FLS contour with the 'smooth' flag enabled:

	<robofab.pens.adapterPens.SegmentToPointPen object at 0x04B7D0B0>
	Traceback (most recent call last):
	  File "<string>", line 10, in ?
	  File "C:\UsersLocal\cosimo.lupo\Documents\GitHub\robofab\Lib\robofab\objects\objectsFL.py", line 1851, in insertSegment
	    node.alignment = flSMOOTH
	NameError: global name 'node' is not defined