Don't insert additional newlines when using [*] tags

[*] tags are special, in that they generate a [list] tag which is then
evaluated as normal. The implementation here would previously have
inserted a "\n" at the end of a [list], which would get converted to a
<br/> in the generated HTML, making it not quite the same thing as
using [list] directly.

Here, we just remove the added "\n" to get identical behaviour between
direct use of [list] and use of [*].