Fix calculation of number of bound sockets to use

Github-Pull: bitcoin#9253
Rebased-From: 9e1f468

src/init.cpp

@@ -854,7 +854,9 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
     }
 
     // Make sure enough file descriptors are available
-    int nBind = std::max((int)mapArgs.count("-bind") + (int)mapArgs.count("-whitebind"), 1);
+    int nBind = std::max(
+                (mapMultiArgs.count("-bind") ? mapMultiArgs.at("-bind").size() : 0) +
+                (mapMultiArgs.count("-whitebind") ? mapMultiArgs.at("-whitebind").size() : 0), size_t(1));
     int nUserMaxConnections = GetArg("-maxconnections", DEFAULT_MAX_PEER_CONNECTIONS);
     nMaxConnections = std::max(nUserMaxConnections, 0);