OCaml: Spurious indent added after 'in'

[jonsterling]

In Topiary 0.6.0, the following formatting was used:

    let attrs =
      let xmlns_attrs = List.map render_xmlns_prefix prefixes_to_add in
      attrs @ xmlns_attrs
    in
    [P.std_tag name attrs content]

In Topiary 0.6.1, this has turned to the following, which I consider undesirable:

    let attrs =
      let xmlns_attrs = List.map render_xmlns_prefix prefixes_to_add in
      attrs @ xmlns_attrs
    in
      [P.std_tag name attrs content]

I believe that this the circumstances under which this occurs at the following: when both the definiens of the let-binding is multi-line, and in is not followed by another let.

[yannham]

I haven't looked deeply, but might be related to #939 (comment) ?

[yannham]

(And thus related to #943)