Adjust statscore for captures

Instead of using quiet histories use capture history with a different
offset.

Passed STC:
https://tests.stockfishchess.org/tests/view/6731d5cc86d5ee47d953e719
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 428896 W: 111160 L: 110269 D: 207467
Ptnml(0-2): 1220, 50296, 110534, 51169, 1229

Passed LTC:
https://tests.stockfishchess.org/tests/view/6733d9fd86d5ee47d953e962
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 105882 W: 26918 L: 26458 D: 52506
Ptnml(0-2): 66, 11430, 29482, 11904, 59

closes official-stockfish/Stockfish#5679

Bench: 840721

src/search.cpp

@@ -1181,9 +1181,14 @@ Value Search::Worker::search(
         else if (move == ttData.move)
             r -= 1879;
 
-        ss->statScore = 2 * thisThread->mainHistory[us][move.from_to()]
-                      + (*contHist[0])[movedPiece][move.to_sq()]
-                      + (*contHist[1])[movedPiece][move.to_sq()] - 3996;
+        if (capture)
+            ss->statScore =
+              thisThread->captureHistory[movedPiece][move.to_sq()][type_of(pos.captured_piece())]
+              - 13000;
+        else
+            ss->statScore = 2 * thisThread->mainHistory[us][move.from_to()]
+                          + (*contHist[0])[movedPiece][move.to_sq()]
+                          + (*contHist[1])[movedPiece][move.to_sq()] - 3996;
 
         // Decrease/increase reduction for moves with a good/bad history (~8 Elo)
         r -= ss->statScore * 1287 / 16384;