Tweak the cutnode depth condition for TT cutoffs
Passed STC:
https://tests.stockfishchess.org/tests/view/67ab396ab5c93ee812d851f3
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 83648 W: 21964 L: 21571 D: 40113
Ptnml(0-2): 339, 9779, 21217, 10128, 361
Passed LTC:
https://tests.stockfishchess.org/tests/view/67ab9647133d55b1d3bc171e
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 68160 W: 17551 L: 17166 D: 33443
Ptnml(0-2): 62, 7353, 18870, 7728, 67
closes https://github.com/official-stockfish/Stockfish/pull/5876
Bench: 3087275