DES MOINES — Iowa gamblers were all in on sports wagers in January, driving betting activity to a monthly record $149.5 million.With college and professional football playoffs in full swing and sportsbooks flourishing without in-person registration requirements, “it truly was an unbelievable month for sports wagering,” said Brian Ohorilko, administrator of the state Racing and Gaming Commission.Legal sports wagering in Iowa topped the $100 million plateau in January for the second straight month, and it was the fourth month in a row for record-setting growth.