Fix some issues with qualified array expansion.

$(other.array[$(other.list)]) would expand to
$(other#array[$(other.list)]) in output due to issues mapping remote
lists to "this" scope. Fix skips the outer "." to properly map.

Fixes [Issue #1998](https://cfengine.com/dev/issues/1998), [Mantis #1128](https://cfengine.com/bugtracker/view.php?id=1128)

Still working on fix for wider expansion/mapping issues.