Avoid querying DNS seeds, if we have open connections.

The goal is to increase independence and privacy.

Rebased-From: 2e7009d

src/net.cpp

@@ -1166,6 +1166,18 @@ void MapPort(bool)
 
 void ThreadDNSAddressSeed()
 {
+    // goal: only query DNS seeds if address need is acute
+    if ((addrman.size() > 0) &&
+        (!GetBoolArg("-forcednsseed", false))) {
+        MilliSleep(11 * 1000);
+
+        LOCK(cs_vNodes);
+        if (vNodes.size() >= 2) {
+            LogPrintf("P2P peers available. Skipped DNS seeding.\n");
+            return;
+        }
+    }
+
     const vector<CDNSSeedData> &vSeeds = Params().DNSSeeds();
     int found = 0;