[net] add seed.testnet.bitcoin.sprovoost.nl to testnet DNS seeds

src/chainparams.cpp

@@ -231,6 +231,7 @@ public:
         // nodes with support for servicebits filtering should be at the top
         vSeeds.emplace_back("testnet-seed.bitcoin.jonasschnelli.ch", true);
         vSeeds.emplace_back("seed.tbtc.petertodd.org", true);
+        vSeeds.emplace_back("seed.testnet.bitcoin.sprovoost.nl", true);
         vSeeds.emplace_back("testnet-seed.bluematt.me", false);
 
         base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);