A 25-year-old Ecuadorean migrant wanted for the brutal sexual assault of a 13-year-old girl at a Queens park was nabbed after good Samaritans smacked him around and tied him up with a belt. “I seen him a few times — he comes to this store to buy stuff,” Jeffrey Flores, who pounced on the creep. “I waited for him. I waited the whole day to see if he would come up. He came at night. “He came in, we went to buy something,” Flores, 24, told The Post. “I saw what he was trying to do, he looked back at...