Fix periodic stats reporting.

The time interval was being reset every time a new connection came in.

server/stats.go

@@ -22,6 +22,7 @@ var (
 func statsThread() {
 	var numClientIP, numConnections uint64
 	prevTime := time.Now()
+	deadline := time.After(statsInterval)
 	for {
 		select {
 		case v := <-statsChannel:
@@ -29,7 +30,7 @@ func statsThread() {
 				numClientIP += 1
 			}
 			numConnections += 1
-		case <-time.After(statsInterval):
+		case <-deadline:
 			now := time.Now()
 			log.Printf("in the past %.g s, %d/%d connections had client_ip",
 				(now.Sub(prevTime)).Seconds(),
@@ -37,6 +38,7 @@ func statsThread() {
 			numClientIP = 0
 			numConnections = 0
 			prevTime = now
+			deadline = time.After(statsInterval)
 		}
 	}
 }