VVLTC parameters tweak
Passed VVLTC with stc bounds:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 91508 W: 24212 L: 23887 D: 43409
Ptnml(0-2): 6, 7863, 29690, 8190, 5
https://tests.stockfishchess.org/tests/view/6a522f515529b8472df803a4
Passed VVLTC with ltc bounds:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 62296 W: 16446 L: 16117 D: 29733
Ptnml(0-2): 6, 5333, 20143, 5658, 8
https://tests.stockfishchess.org/tests/view/6a52d9e65529b8472df805a5
closes https://github.com/official-stockfish/Stockfish/pull/6981
Bench: 2792255