[FIX] mail: remove attachment when clicking on white cross icon

Before this commit, we could not remove an attachment in the composer
by clicking on the white-cross icon that is shown on mouse hover.

This was due to the handler function picking the wrong DOM element
as target for reading on the attachment ID: it should pick the target
of this handler function, and not the specific target below the mouse
on click. For instance, let's consider this HTML snippet for the button:

    ```
    <div class='delete' data-attachment-id=100>
        <span class='cross-icon'>X</span>
    </div>
    ```

where the handler function is called when clicking on `div.delete`.

When we click on `span.cross-icon`, it triggers the handler function
of `div.delete`. The MouseEvent object contains the following property
values:

    - `target`: the `<span>` element
    - `currentTarget`: the `<div>` element

The handler function of `div.delete` deletes an attachment by looking
into the `data-attachment-id` attribute of `div.delete`. It should
always pick `div.delete`, even when the user clicks on `span.cross-icon`.

0 files changed, 0 insertions, 0 deletions