[CSL-1081] Get rid of useless blockDifficultyIncrement
[CSL-1081] Get rid of useless blockDifficultyIncrement

input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype