extractor.instagram.filename does not exist for videos

[rEnr3n]

I name my files like this:

"instagram": {
    "filename": "{filename}.{extension}"
},

The filename looks like 60274315_114384806458139_6166801734221692787_n.jpg for images.
However, it doesn't work for videos. I would get None.mp4 instead.

$ gallery-dl -Kv https://www.instagram.com/p/Bqxp0VSBgJg/
[gallery-dl][debug] Version 1.8.4
[gallery-dl][debug] Python 3.7.3 - Linux-5.1.4-arch1-1-ARCH-x86_64-with-arch
[gallery-dl][debug] requests 2.22.0 - urllib3 1.25.2
[gallery-dl][debug] Starting KeywordJob for 'https://www.instagram.com/p/Bqxp0VSBgJg/'
[instagram][debug] Using InstagramImageExtractor for 'https://www.instagram.com/p/Bqxp0VSBgJg/'
[urllib3.connectionpool][debug] Starting new HTTPS connection (1): www.instagram.com:443
[urllib3.connectionpool][debug] https://www.instagram.com:443 "GET /p/Bqxp0VSBgJg/ HTTP/1.1" 200 15188
Keywords for directory names:
-----------------------------
category
  instagram
date
  2018-11-29 19:23:58
display_url
  https://instagram.fmnl14-1.fna.fbcdn.net/vp/a1da4f42c4ea4e0c744d23ff6ee7538f/5CF3AD25/t51.2885-15/e15/44881419_334653380687029_938249642122187494_n.jpg?_nc_ht=instagram.fmnl14-1.fna.fbcdn.net
fullname
  Instagram
height
  640
likes
  342199
media_id
  1923502432034620000
owner_id
  25025320
shortcode
  Bqxp0VSBgJg
subcategory
  image
typename
  GraphVideo
username
  instagram
width
  640

Keywords for filenames and --filter:
------------------------------------
category
  instagram
date
  2018-11-29 19:23:58
display_url
  https://instagram.fmnl14-1.fna.fbcdn.net/vp/a1da4f42c4ea4e0c744d23ff6ee7538f/5CF3AD25/t51.2885-15/e15/44881419_334653380687029_938249642122187494_n.jpg?_nc_ht=instagram.fmnl14-1.fna.fbcdn.net
fullname
  Instagram
height
  640
likes
  342199
media_id
  1923502432034620000
owner_id
  25025320
shortcode
  Bqxp0VSBgJg
subcategory
  image
typename
  GraphVideo
username
  instagram
width
  640

Can we have the filename option for instagram videos as well? JDownloader would get the filename as 46829315_580232102421636_8062508454817824768_n.mp4, which is what I want.