Crash on external .scad file change

[paulirotta]

Editing a file in VSCode resulted in a crash. Running PR3.1. I haven't seen the previously with the same workflow on Linux Mint so it may be a recent regression. The editor in OpenSCAD was not visiable. I'll update if I find a more reproducible scenario.

[t-paul]

Please try with RC4, there's a crash fix for warning messages that could be related.

[paulirotta]

Not seen so far in RC4. Will update if that changes.

[t-paul]

As there's no new report, I'm assuiming it's fixed in RC4 and later.