Ian Moody <moz-ian@perix.co.uk> [Fri, 08 Mar 2019 23:45:12 +0000] rev 41900
py3: convert indexes into bytes when enumerating lists in urlencodenested
Otherwise it'll try to insert them them into a %s slot in a b'' later and fail.
Differential Revision: https://phab.mercurial-scm.org/D6105