Simplify shallow depth pruning for anti variants

Simplify shallow depth pruning for anti variants

giveaway STC
LLR: 2.96 (-2.94,2.94) [-10.00,5.00]
Total: 1787 W: 698 L: 655 D: 434
http://www.variantfishtest.org:6543/tests/view/601e7a7a6e23db669974e823

giveaway LTC
LLR: 2.96 (-2.94,2.94) [-10.00,5.00]
Total: 1501 W: 550 L: 507 D: 444
http://www.variantfishtest.org:6543/tests/view/601ecee96e23db669974e834

losers STC
LLR: 2.99 (-2.94,2.94) [-10.00,5.00]
Total: 14506 W: 6366 L: 6407 D: 1733
http://www.variantfishtest.org:6543/tests/view/601e7a8f6e23db669974e827

losers LTC
LLR: 2.96 (-2.94,2.94) [-10.00,5.00]
Total: 3939 W: 1740 L: 1707 D: 492
http://www.variantfishtest.org:6543/tests/view/601fbb036e23db669974e846