removed unused code in INV message

vToFetch is never used after declaration. When checked if not empty,
evaluation is always false. Best case scenario this is optimized by the
compiler, worst case it wastes  cpu cycles.  It should be removed either
way.

src/net_processing.cpp

@@ -1552,8 +1552,6 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
 
         uint32_t nFetchFlags = GetFetchFlags(pfrom);
 
-        std::vector<CInv> vToFetch;
-
         for (unsigned int nInv = 0; nInv < vInv.size(); nInv++)
         {
             CInv &inv = vInv[nInv];
@@ -1593,9 +1591,6 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
             // Track requests for our stuff
             GetMainSignals().Inventory(inv.hash);
         }
-
-        if (!vToFetch.empty())
-            connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vToFetch));
     }