When starting to draw with the polygon tool, the first two points aren't connected

[petebankhead]

Bug report

Describe the bug
When drawing a polygon with individual clicks (rather than click & drag), the first two points aren't connected.

This is only really a visual issue, and the connection occurs when an additional point is drawn.

To Reproduce
Steps to reproduce the behavior:

1. Open an image & turn on the polygon tool
2. Click once to add the first point
3. Mouse the cursor
4. A line should connect the cursor to the original point... but doesn't

Expected behavior
The points are connected when drawing.

Desktop (please complete the following information):

• OS: All
• QuPath Version: 0.4.0

Additional context
This has come up before and been fixed... but is now somehow broken again.