The loop was ignoring ` nu->pntsv` in this case, resulting in only the
first point of each row being used for snapping.
This commit also simplifies the code by removing the no-snap limitation
when the curve only has 1 point.
This limitation existed because the curve is not visible in this case.
But this is contradictory for when the curve has loose points (which
are also not visible).
a0b232c80d