The interest rate on the most popular U.S. home loan ticked down last week for the first time since the start of the Iran war, but not enough to rejuvenate a housing market that’s pricing out many buyers with a combination of elevated borrowing costs and expensive homes. The Mortgage Bankers Association said Wednesday the contract rate on a 30-year, fixed-rate mortgage fell 6 basis points to 6.51% for the week ended April 3, retreating from the …