Do more aggressive futility pruning for captures

This patch lines up with other patches which use better eval to produce more aggressive cutoffs based on static evaluation of position, it allows more aggressive futility pruning for captures - so now we will be producing them with bigger evaluation of position, so more often.

passed STC
https://tests.stockfishchess.org/tests/view/5f2da79e61e3b6af64881fd2
LLR: 3.87 (-2.94,2.94) {-0.50,1.50}
Total: 27256 W: 3809 L: 3593 D: 19854
Ptnml(0-2): 221, 2578, 7830, 2762, 237

passed LTC
https://tests.stockfishchess.org/tests/view/5f2df92061e3b6af64882012
LLR: 4.97 (-2.94,2.94) {0.25,1.75}
Total: 43624 W: 3095 L: 2820 D: 37709
Ptnml(0-2): 66, 2410, 16608, 2639, 89

closes https://github.com/official-stockfish/Stockfish/pull/2946

Bench: 4272280

src/search.cpp

@@ -1055,7 +1055,7 @@ moves_loop: // When in check, search starts from here
                   && !(PvNode && abs(bestValue) < 2)
                   && PieceValue[MG][type_of(movedPiece)] >= PieceValue[MG][type_of(pos.piece_on(to_sq(move)))]
                   && !ss->inCheck
-                  && ss->staticEval + 267 + 391 * lmrDepth
+                  && ss->staticEval + 178 + 261 * lmrDepth
                      + PieceValue[MG][type_of(pos.piece_on(to_sq(move)))] <= alpha)
                   continue;