Removed extra enumerate() from Query.setup_joins()

        # Then, add the path to the query's joins. Note that we can't trim

        # joins at this stage - we will need the information about join type

        # of the trimmed joins.

        for pos, join in enumerate(path):

        for join in path:

            opts = join.to_opts

            if join.direct:

                nullable = self.is_nullable(join.join_field)