Division by 0 / NaN coordinates

[Duffmann]

Issue: Some combinations of input parameters can result in NaN for X/Y travel coordinates during probing

Root Cause: Division-by-Zero may occur in this code segment:

    let dx = (xmax - xmin) / parseInt((xmax - xmin) / this.delta)
    let dy = (ymax - ymin) / parseInt((ymax - ymin) / this.delta)

Test: (#autolevel P1 X14 Y56)

Background:

• Default Margin is 2.5mm
• Default Delta is 10mm
• For probing-only mode (xmax-xmin) evaluates to X - 5mm. If X < 15mm parseInt((xmax - xmin) / this.delta) evaluates to 0 and dx will evaluate to NaN. Same for dy for Y values < 15mm

Proposed fix: Ensure parseInt(..)-denominator is evaluating to >= 1, e.g.

    let dx = (xmax - xmin) / max(parseInt((xmax - xmin) / this.delta), 1)
    let dy = (ymax - ymin) / max(parseInt((ymax - ymin) / this.delta), 1)

Note: I have not checked for potential side-effects of the proposed fix!

Thanks for this great plugin!