Another try to fix not removing last player.

cmd/mtwebmapper/players.go

@@ -133,13 +133,17 @@ func samePlayers(a, b []*player) bool {
 
 func (ps *players) run() {
 	for {
+		ps.mu.Lock()
+		empty := len(ps.pls) == 0
+		ps.mu.Unlock()
+
 		pls, err := ps.readFromFIFO()
 		if err != nil {
 			//log.Printf("err: %s\n", err)
 			time.Sleep(sleepInterval)
 			continue
 		}
-		if pls == nil {
+		if empty && pls == nil {
 			//log.Println("no players")
 			continue
 		}