try to pick non-slow tunnel

libi2pd/TunnelPool.cpp

@@ -172,13 +172,16 @@ namespace tunnel
 	{
 		if (tunnels.empty ()) return nullptr;
 		uint32_t ind = rand () % (tunnels.size ()/2 + 1), i = 0;
+		bool skipped = false;
 		typename TTunnels::value_type tunnel = nullptr;
 		for (const auto& it: tunnels)
 		{
 			if (it->IsEstablished () && it != excluded)
 			{
-				if(HasLatencyRequirement() && it->LatencyIsKnown() && !it->LatencyFitsRange(m_MinLatency, m_MaxLatency)) {
-					i ++;
+				if (it->IsSlow () || (HasLatencyRequirement() && it->LatencyIsKnown() && 
+				    !it->LatencyFitsRange(m_MinLatency, m_MaxLatency))) 
+				{
+					i++; skipped = true;
 					continue;
 				}
 				tunnel = it;
@@ -186,7 +189,8 @@ namespace tunnel
 			}
 			if (i > ind && tunnel) break;
 		}
-		if(HasLatencyRequirement() && !tunnel) {
+		if (!tunnel && skipped) 
+		{
 			ind = rand () % (tunnels.size ()/2 + 1), i = 0;
 			for (const auto& it: tunnels)
 			{