[CSM-153] Notify about txs only if update is not empty
[CSM-153] Notify about txs only if update is not empty

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