Double indication of values used from opens_codelens causing view scrolling off-by-one erro

When "Indicate what values have been used from an open" is checked in the settings (under `Reason_language_server: Opens_codelens` section of vs code settings) I get one line and one _extra_ line in my code showing the values that the `open` adds to a file. The extra line seems to result in a miscalculation of how many lines are in the file, which results in (an annoying) off-by-one error that scrolls the view unnecessarily by one line whenever I type a key.


In case it helps, this is the `Float` module that I reference in the `Utils` parent module above:

```
module Float = {
let (+) = (+.);
let (-) = (-.);
let ( * ) = ( *. );
let (/) = (/.);
let (~-) = (~-.);
};
```

This is what the off-by-one error does when editing the file (37 sec. video):
https://www.dropbox.com/s/tsp22oawsqubyfq/OffByOne.mp4?dl=0

(Each keypress, after a few hundred milleseconds debounce, results in the view scrolling by one line).

Reproduce the issue with "Indicate what values have been used from an open" enabled under the Reason_language_server: Opens_codelens settings. Compare the displayed codelens lines with the file's actual line count while editing the Float and Utils example. Done means the duplicate indication and one-line scroll on each debounced keypress no longer occur.

Written by the indexing model from the issue text.