Rook Mobility Tweak

Passed STC:
LLR: 2.94 (-2.94,2.94) {-0.25,1.25}
Total: 171152 W: 34715 L: 34202 D: 102235
Ptnml(0-2): 3278, 20155, 38228, 20606, 3309
https://tests.stockfishchess.org/tests/view/5fa861f467cbf42301d6a68e

Passed LTC:
LLR: 2.94 (-2.94,2.94) {0.25,1.25}
Total: 149616 W: 20471 L: 19882 D: 109263
Ptnml(0-2): 1172, 14434, 43102, 14833, 1267
https://tests.stockfishchess.org/tests/view/5fa9c8ff67cbf42301d6a74f

closes https://github.com/official-stockfish/Stockfish/pull/3226

Bench: 3597730