Remove BlockedStorm array
Apparently, only RANK_3 is relevant. This removes a look-up and the
BlockedStorm array, but adds another conditional.
STC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 84340 W: 18054 L: 18054 D: 48232
http://tests.stockfishchess.org/tests/view/5bea10f40ebc595e0ae3457b
LTC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 31874 W: 5135 L: 5032 D: 21707
http://tests.stockfishchess.org/tests/view/5beadb6a0ebc595e0ae35542
Closes https://github.com/official-stockfish/Stockfish/pull/1814
Bench: 3799443