wp widget move --sidebar-id --position puts the widget at the top when the position matches its current index #94

When a widget moves to another sidebar with --position=<n>, it lands at position 1 instead of <n> if <n> is the same as its position in the current sidebar:

$ wp widget move archives-1 --sidebar-id=sidebar-2 --position=2
$ wp widget list sidebar-2 --fields=id,position

Expected archives-1 at position 2, but the list shows:

id	position
archives-1	1
search-2	2

Widget_Command::move() sets the new index to the current index when --position is not given, and then resets it to 0 for a move to another sidebar if the new index equals the current index. That check cannot tell "no --position" from "--position that happens to match the current index", so the given position is ignored.

Expected: archives-1 is at position 2 in sidebar-2.