net: constify a few CNode vars to indicate that they're threadsafe

src/net.cpp

@@ -2512,9 +2512,13 @@ unsigned int CConnman::GetSendBufferSize() const{ return nSendBufferMaxSize; }
 CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, const std::string& addrNameIn, bool fInboundIn) :
     ssSend(SER_NETWORK, INIT_PROTO_VERSION),
     addr(addrIn),
+    fInbound(fInboundIn),
+    id(idIn),
     nKeyedNetGroup(nKeyedNetGroupIn),
     addrKnown(5000, 0.001),
-    filterInventoryKnown(50000, 0.000001)
+    filterInventoryKnown(50000, 0.000001),
+    nLocalServices(nLocalServicesIn),
+    nMyStartingHeight(nMyStartingHeightIn)
 {
     nServices = NODE_NONE;
     nServicesExpected = NODE_NONE;
@@ -2533,7 +2537,6 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     fOneShot = false;
     fClient = false; // set by version message
     fFeeler = false;
-    fInbound = fInboundIn;
     fNetworkNode = false;
     fSuccessfullyConnected = false;
     fDisconnect = false;
@@ -2562,12 +2565,8 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     minFeeFilter = 0;
     lastSentFeeFilter = 0;
     nextSendTimeFeeFilter = 0;
-    id = idIn;
     nOptimisticBytesWritten = 0;
-    nLocalServices = nLocalServicesIn;
-
     GetRandBytes((unsigned char*)&nLocalHostNonce, sizeof(nLocalHostNonce));
-    nMyStartingHeight = nMyStartingHeightIn;
 
     BOOST_FOREACH(const std::string &msg, getAllNetMessageTypes())
         mapRecvBytesPerMsgCmd[msg] = 0;

src/net.h

@@ -589,7 +589,7 @@ public:
     bool fFeeler; // If true this node is being used as a short lived feeler.
     bool fOneShot;
     bool fClient;
-    bool fInbound;
+    const bool fInbound;
     bool fNetworkNode;
     bool fSuccessfullyConnected;
     bool fDisconnect;
@@ -603,7 +603,7 @@ public:
     CCriticalSection cs_filter;
     CBloomFilter* pfilter;
     int nRefCount;
-    NodeId id;
+    const NodeId id;
 
     const uint64_t nKeyedNetGroup;
 protected:
@@ -679,8 +679,8 @@ private:
 
     uint64_t nLocalHostNonce;
     // Services offered to this peer
-    ServiceFlags nLocalServices;
+    const ServiceFlags nLocalServices;
-    int nMyStartingHeight;
+    const int nMyStartingHeight;
 public:
 
     NodeId GetId() const {