fix warnings

Author: Aurélien Richez

src/main/scala/io/iohk/ethereum/domain/Blockchain.scala

@@ -176,7 +176,6 @@ class BlockchainImpl(
     log.debug(s"Trying to remove block ${block.idTag}")
 
     val txList = block.body.transactionList
-    val bestBlockNumber = blockchainReader.getBestBlockNumber()
     val latestCheckpointNumber = getLatestCheckpointBlockNumber()
 
     val blockNumberMappingUpdates =

src/test/scala/io/iohk/ethereum/blockchain/sync/EphemBlockchainTestSetup.scala

@@ -1,6 +1,5 @@
 package io.iohk.ethereum.blockchain.sync
 
-import io.iohk.ethereum.Fixtures
 import io.iohk.ethereum.db.components.EphemDataSourceComponent
 import io.iohk.ethereum.db.components.Storages
 import io.iohk.ethereum.db.storage.pruning.ArchivePruning

src/test/scala/io/iohk/ethereum/consensus/ConsensusSpec.scala

@@ -22,7 +22,6 @@ import io.iohk.ethereum.consensus.validators.BlockHeaderError.HeaderParentNotFou
 import io.iohk.ethereum.consensus.validators._
 import io.iohk.ethereum.db.storage.MptStorage
 import io.iohk.ethereum.domain._
-import io.iohk.ethereum.domain.appstate.BestBlockInfo
 import io.iohk.ethereum.ledger.BlockData
 import io.iohk.ethereum.ledger.BlockExecution
 import io.iohk.ethereum.ledger.BlockQueue.Leaf