GhostRider algorithm (Raptoreum) support

src/base/net/stratum/EthStratumClient.h

@@ -57,6 +57,12 @@ private:
 
     bool m_authorized   = false;
     std::pair<uint64_t, String> m_extraNonce{};
+
+#   ifdef XMRIG_ALGO_GHOSTRIDER
+    uint64_t m_extraNonce2Size = 0;
+    uint64_t m_nextDifficulty = 0;
+    String m_ntime;
+#   endif
 };