Valentina produces wrong seam allowance for rollback case.

[Roman Telezhynskyi]

In case where first point in a main path must rollback seam allowance to produce correct result Valentina cannot do it. This happens because on this stage we don't have points to rollback.

[Roman Telezhynskyi]

Fixed issue #923. Valentina produces wrong seam allowance for rollback case.

→ <<cset 111ae73392a2>>

[Roman Telezhynskyi]

Fixed issue #923. Valentina produces wrong seam allowance for rollback case. (grafted from 111ae73392a265baecbb3031cf3963682e0bea77)

→ <<cset c3da29d81cc4>>