Tweak bishop pair and knight weight

A combo of two patches that failed SPRT with score
higher than 50% but togheter they succeed:

SPRT at 60+0.05
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 7312 W: 1276 L: 1139 D: 4897

bench: 8029334

src/material.cpp

@@ -39,7 +39,7 @@ namespace {
   const Value RedundantRook  = Value(554);
 
   //                                  pair  pawn knight bishop rook queen
-  const int LinearCoefficients[6] = { 1617, -162, -1172, -190,  105,  26 };
+  const int LinearCoefficients[6] = { 1817, -162, -1122, -190,  105,  26 };
 
   const int QuadraticCoefficientsSameColor[][PIECE_TYPE_NB] = {
     // pair pawn knight bishop rook queen