Remove restriction about base fee on eth_sendRawTransaction (#1473)

Signed-off-by: Abdelhamid Bakhta <abdelhamid.bakhta@consensys.net>

ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/PendingTransactions.java

@@ -273,7 +273,8 @@ public class PendingTransactions {
     final TransactionInfo existingTransaction =
         getTrackedTransactionBySenderAndNonce(transactionInfo);
     if (existingTransaction != null) {
-      if (!transactionReplacementHandler.shouldReplace(
+      if (existingTransaction.transaction.isFrontierTransaction()
+          && !transactionReplacementHandler.shouldReplace(
               existingTransaction, transactionInfo, chainHeadHeaderSupplier.get())) {
         return REJECTED_UNDERPRICED_REPLACEMENT;
       }

ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionPool.java

@@ -160,15 +160,17 @@ public class TransactionPool implements BlockAddedObserver {
 
   public ValidationResult<TransactionInvalidReason> addLocalTransaction(
       final Transaction transaction) {
+    if (transaction.isFrontierTransaction()
+        && (!ExperimentalEIPs.eip1559Enabled || this.eip1559.isEmpty())) {
       final Wei transactionGasPrice = minTransactionGasPrice(transaction);
       if (transactionGasPrice.compareTo(minTransactionGasPrice) < 0) {
         return ValidationResult.invalid(TransactionInvalidReason.GAS_PRICE_TOO_LOW);
       }
-
       if (!configuration.getTxFeeCap().isZero()
           && transactionGasPrice.compareTo(configuration.getTxFeeCap()) > 0) {
         return ValidationResult.invalid(TransactionInvalidReason.TX_FEECAP_EXCEEDED);
       }
+    }
 
     final ValidationResult<TransactionInvalidReason> validationResult =
         validateTransaction(transaction);