Revert "Reduce When TTValue is Above Alpha"
The patch regressed significantly at longer time controls. In
particular, the `depth--` behavior was predicted to scale badly based on
data from other variations of the patch.
Passed VVLTC 1st sprt:
https://tests.stockfishchess.org/tests/view/664d45cf830eb9f886616c7d
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 51292 W: 13242 L: 12954 D: 25096
Ptnml(0-2): 5, 4724, 15896, 5020, 1
Passed VVLTC 2nd sprt:
https://tests.stockfishchess.org/tests/view/664e641a928b1fb18de4e385
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 41884 W: 10933 L: 10634 D: 20317
Ptnml(0-2): 1, 3759, 13125, 4054, 3
closes https://github.com/official-stockfish/Stockfish/pull/5283
Bench: 1503815