By Richard Cowan WASHINGTON (Reuters) -A bipartisan group of U.S. senators on Thursday decided to put off until after the Nov. 8 congressional elections any vote on legislation protecting gay marriage, dashing the hopes of advocates who sought prompt action on a bill already passed by the House of Representatives. The move came after weeks of closed-door talks between a small group of Democratic and Republican senators who looked at ways to amend the House bill in order to attract at least 10 Republican supporters who would join 48 Democrats and two independents. The U.S. Census Bureau in 2019…