[CSL-1555] Revert change to DB key serialization in 'update/'
[CSL-1555] Revert change to DB key serialization in 'update/'

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