net: Log accepted connection after m_nodes.push_back

Otherwise, the debug log could read confusingly, when the getpeerinfo()
RPC (calling GetNodeStats) happens after the "accepted connection" log
line, but returns an empty list.

For example, the following timeline in the debug log could correspond to
a getpeerinfo reply that is empty:

[net] [net.cpp:3764] [CNode] Added connection peer=0
[net] [net.cpp:1814] [CreateNodeFromAcceptedSocket] connection from 127.0.0.1:45154 accepted
[http] [httpserver.cpp:305] [http_request_cb] Received a POST request for / from 127.0.0.1:33320
[httpworker.1] [rpc/request.cpp:232] [parse] ThreadRPCServer method=getpeerinfo user=__cookie__

Fix it by moving the log line.

src/net.cpp

@@ -1810,13 +1810,11 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                              });
     pnode->AddRef();
     m_msgproc->InitializeNode(*pnode, nLocalServices);
-
-    LogPrint(BCLog::NET, "connection from %s accepted\n", addr.ToStringAddrPort());
-
     {
         LOCK(m_nodes_mutex);
         m_nodes.push_back(pnode);
     }
+    LogDebug(BCLog::NET, "connection from %s accepted\n", addr.ToStringAddrPort());
 
     // We received a new connection, harvest entropy from the time (and our peer count)
     RandAddEvent((uint32_t)id);