Chore(booking-job): Increase threads

backend/internal/ktmtrainbot/backgroundbookingjob.go

@@ -200,7 +200,7 @@ func (env *Env) startBooking(job *Booking, username string, password string, cre
 	contact := job.Contact
 	reverse := job.BackToSg
 
-	threadCount := 10
+	threadCount := 15
 	for i := 0; i < threadCount; i++ {
 		time.Sleep(time.Millisecond * 100)
 		go func() {