fix concurrent modification exception for bonsai trie(hyperledger#2152)

Signed-off-by: Karim TAAM <karim.t2am@gmail.com>

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/bonsai/BonsaiWorldStateUpdater.java

@@ -37,6 +37,7 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Function;
 
 import org.apache.tuweni.bytes.Bytes;
@@ -53,7 +54,8 @@ public class BonsaiWorldStateUpdater extends AbstractWorldUpdater<BonsaiWorldVie
   // storage sub mapped by _hashed_ key.  This is because in self_destruct calls we need to
   // enumerate the old storage and delete it.  Those are trie stored by hashed key by spec and the
   // alternative was to keep a giant pre-image cache of the entire trie.
-  private final Map<Address, Map<Hash, BonsaiValue<UInt256>>> storageToUpdate = new HashMap<>();
+  private final Map<Address, Map<Hash, BonsaiValue<UInt256>>> storageToUpdate =
+      new ConcurrentHashMap<>();
 
   BonsaiWorldStateUpdater(final BonsaiWorldView world) {
     super(world);