Fix spiral vase mode

[EmperorArthur]

• Fixed assertion relating to walls.
• Switched to profile_wall instead of profile_wall_sub.
• Adjusted block_pinch offset so the stacking lip is properly printed.

Fixes #180

Left is new, right is old.

[jpypi]

Should the side square indent top be lowered to match the look of the old one or is that performing some structural duties?

[EmperorArthur]

Should the side square indent top be lowered to match the look of the old one or is that performing some structural duties?

It could be lowered. I'll look into it.

[EmperorArthur]

@jpypi Done.

[jpypi]

Looks great!

[powturns]

I've tried this with the default settings and various nozzle values; however, I slice in prusa slicer with a 0.6 nozzle, it is missing walls.

Eg:

Measuring the walls on previous versions, it seems like they are much thicker.

This version walls:

Previous version walls:

Edit: Looks like this is the same as: https://github.com/kennetek/gridfinity-rebuilt-openscad/issues/131