Auto merge of #3098 - str4d:2343-overwinter-disable-mempooltxinputlimit, r=str4d

Ignore -mempooltxinputlimit once Overwinter activates

Overwinter changes the SignatureHash function to solve the quadratic hashing problem, so this option will no longer be needed.

src/wallet/wallet.cpp

@@ -2775,6 +2775,12 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
 
                 // Check mempooltxinputlimit to avoid creating a transaction which the local mempool rejects
                 size_t limit = (size_t)GetArg("-mempooltxinputlimit", 0);
+                {
+                    LOCK(cs_main);
+                    if (NetworkUpgradeActive(chainActive.Height() + 1, Params().GetConsensus(), Consensus::UPGRADE_OVERWINTER)) {
+                        limit = 0;
+                    }
+                }
                 if (limit > 0) {
                     size_t n = txNew.vin.size();
                     if (n > limit) {