Use same pawn value in both nets when doing material scaling of eval
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 221312 W: 57291 L: 57274 D: 106747
Ptnml(0-2): 760, 26152, 56841, 26117, 786
https://tests.stockfishchess.org/tests/view/676e2a101a2f267f20548453
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 176808 W: 45084 L: 45023 D: 86701
Ptnml(0-2): 112, 19418, 49286, 19473, 115
https://tests.stockfishchess.org/tests/view/676f424d1a2f267f2054857f
closes https://github.com/official-stockfish/Stockfish/pull/5741
Bench: 1121800