Tweak futility pruning for extinction variants

Tweak futility pruning for extinction variants

atomic STC
LLR: 2.96 (-2.94,2.94) [0.00,10.00]
Total: 2994 W: 1118 L: 999 D: 877
http://www.variantfishtest.org:6543/tests/view/6014099b6e23db669974e628

atomic LTC
LLR: 2.97 (-2.94,2.94) [0.00,10.00]
Total: 4099 W: 1416 L: 1287 D: 1396
http://www.variantfishtest.org:6543/tests/view/601425556e23db669974e63a

extinction STC
LLR: 2.96 (-2.94,2.94) [0.00,10.00]
Total: 496 W: 279 L: 177 D: 40
http://www.variantfishtest.org:6543/tests/view/601409d26e23db669974e62f

extinction LTC
LLR: 2.97 (-2.94,2.94) [0.00,10.00]
Total: 794 W: 410 L: 305 D: 79
http://www.variantfishtest.org:6543/tests/view/601445566e23db669974e643

kinglet STC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 1223 W: 587 L: 479 D: 157
http://www.variantfishtest.org:6543/tests/view/601441fc6e23db669974e641

kinglet LTC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 994 W: 480 L: 376 D: 138
http://www.variantfishtest.org:6543/tests/view/601445906e23db669974e645