net: Send post-verack handshake messages at most once

Github-Pull: #20146
Rebased-From: fa1f6f237d

src/net_processing.cpp

@@ -2119,6 +2119,8 @@ bool ProcessMessage(CNode* pfrom, const std::string& msg_type, CDataStream& vRec
 
     if (msg_type == NetMsgType::VERACK)
     {
+        if (pfrom->fSuccessfullyConnected) return true;
+
         pfrom->SetRecvVersion(std::min(pfrom->nVersion.load(), PROTOCOL_VERSION));
 
         if (!pfrom->fInbound) {