fix: do not change sign of residual form in realclassify.lib
(cherry picked from commit 3ac9114362c0eb5bc8d012d4a95b6bc92a7bc2ac)

Signed-off-by: Andreas Steenpass <steenpass@mathematik.uni-kl.de>
Merge pull request #519 from steenpass/realclassify_sw

fix: do not change sign of residual form in realclassify.lib