Do not fail if media info fails

[data-retriever]

(plus running it through cargo fmt)

For instance checking https://download.blender.org/demo/movies/BBB/bbb_sunflower_1080p_60fps_normal.mp4
It will show all the tracks:

$ cargo run --example mp4info  ~/bbb_sunflower_1080p_60fps_normal.mp4
File:
  file size:          355856562
  major_brand:        isom
  compatible_brands:  isom avc1 

Movie:
  version:        0
  creation time:  1387216772
  duration:       634.533s
  fragments:      false
  timescale:      600

Found 3 Tracks
  Track: #1(und) Video: h264 (High) (avc1 / 0x61766331), 1920x1080, 4004 kb/s, 60.00 fps
  Track: #3(und) Audio: mp4a box not found
  Track: #2(und) Audio: aac (-) (mp4a / 0x6D703461), 96000 Hz, -, 160 kb/s

[alfg]

Thank you!