Avoid 'timing mishap' warnings when mocking

src/net_processing.cpp

@@ -3637,7 +3637,7 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat
                     // Matching pong received, this ping is no longer outstanding
                     bPingFinished = true;
                     const auto ping_time = ping_end - pfrom.m_ping_start.load();
-                    if (ping_time.count() > 0) {
+                    if (ping_time.count() >= 0) {
                         // Successful ping time measurement, replace previous
                         pfrom.nPingUsecTime = count_microseconds(ping_time);
                         pfrom.nMinPingUsecTime = std::min(pfrom.nMinPingUsecTime.load(), count_microseconds(ping_time));