rpc: only add wit-nonce if segwit is active (submitblock).

lib/http/rpc.js

@@ -1467,7 +1467,7 @@ RPC.prototype.submitblock = co(function* submitblock(args) {
   block = Block.fromRaw(toString(args[0]), 'hex');
 
   // Fix eloipool bug (witness nonce is not present).
-  if (block.getCommitmentHash()) {
+  if (this.chain.state.hasWitness() && block.getCommitmentHash()) {
     tx = block.txs[0];
     if (!tx.hasWitness()) {
       this.logger.warning('Submitted block had no witness nonce.');