InstaLooter doesn't download images/videos at the highest possible resolution

## Library version

*What's the installed library version ? Check with `instalooter --version`*:

```
instalooter v2.4.0
```

## Environment

*Describe here your environment, including:*

* Windows 7
* Python 3.7.4

### Expected behaviour

Should download content at original resolution. Just like Deskgram.net does for images (1440x1800)...
https://deskgram.net/instagram
-> https://deskgram.net/p/2088004085562292841_25025320
--> https://instagram.frix8-1.fna.fbcdn.net/vp/0b7cb657774a0b0361c933f1cda78a2f/5DA53F50/t51.2885-15/e35/66045526_1049505828588111_2056921069788846425_n.jpg?_nc_ht=instagram.frix8-1.fna.fbcdn.net&se=8&ig_cache_key=MjA4ODAwNDA4NTU2MjI5Mjg0MQ%3D%3D.2

...and for videos at original/higher resolution (720x900)
-> https://deskgram.cc/p/2120618038205228166_25025320
--> https://instagram.frix8-1.fna.fbcdn.net/v/t50.2886-16/70168759_451118545473762_5648733325471143296_n.mp4?efg=eyJ2ZW5jb2RlX3RhZyI6InZ0c192b2RfdXJsZ2VuLjcyMC5mZWVkIn0&_nc_ht=instagram.frix8-1.fna.fbcdn.net&_nc_cat=106&vs=17876310568431912_3774079448&_nc_vs=HBksFQAYJEdMZXdMZ1Rpa0tjNFNwb0JBSUJWbnY4SFZXUk9ia1lMQUFBRhUAABUAGCRHRVlVS0FTcG1hbVhzXzhCQU5zM3pSWVlaM1lSYmtZTEFBQUYVAgAoABgAGwGIB3VzZV9vaWwBMBUAABgAFtDP386bmsE%2FFQIZBRgCQzMsF0AjVP3ztkWiGBJkYXNoX2Jhc2VsaW5lXzFfdjERAHXqBwA%3D&_nc_rid=959f7159cf&oe=5D944023&oh=440d542f85de69b0e5d1905f88655982

(--> thumbnail also 720x900) https://instagram.frix8-1.fna.fbcdn.net/v/t51.2885-15/e35/67945472_162855124770232_2354734316477471544_n.jpg?_nc_ht=instagram.frix8-1.fna.fbcdn.net&_nc_cat=1&oh=5e42b6037d509e6f50648ac152c6719d&oe=5D94B28B

### Actual behaviour

InstaLooter downloads images at smaller resolution (1080x1350, resizer "p1080x1080" in url), example
https://www.instagram.com/instagram/
-> https://www.instagram.com/p/B19R3Glh1LI/
--> https://scontent-arn2-2.cdninstagram.com/vp/9954f7fe51473567d2b0ffa4729f07a5/5E1AC55F/t51.2885-15/e35/p1080x1080/69793183_132808534661341_3847812104607006106_n.jpg?_nc_ht=scontent-arn2-2.cdninstagram.com&_nc_cat=1

InstaLooter also downloads smaller version (480x600) of videos, example
https://www.instagram.com/p/B1t8t7HgiSG/
-->
instagram\2019-08-28_18-38-19_UTC.mp4
Format : MPEG-4 at 749 kb/s
Length : 898 KiB for 9 s 823 ms

Video #0 : AVC at 688 kb/s
Aspect : 480 x 600 (0.800) at 30.000 fps

Audio #0 : AAC at 64.2 kb/s
Infos : 2 channels, 44.1 kHz