0.21.12: Fix bug with scale sorting.

Negative values was sorted after zero value, but with reverse order: 10, 9, 8, 7, 1, 0, -10, -9, -8, -1. Now it fixed and order is correct: 10, 9, 8, 7, 1, 0, -1, -8, -9, -10.

Bug was hiding from us for almost 3 and half years and was reported by @justtoask2.