20160715-1: Fix backend misusage
Fix a bug that could lead to using only the last backend for all hostnames due to variable redefining. See https://play.golang.org/p/yjiEENusQs as an illustration
Fix a bug that could lead to using only the last backend for all hostnames due to variable redefining. See https://play.golang.org/p/yjiEENusQs as an illustration