[Bug] First storyboard is always broken

[iBicha]

Describe the bug
/videos/:id consistently returns storyboards where the first one has interval set to zero, and the link to the image does not work

Steps to Reproduce

1. /api/v1/videos/UhbixyxgsiU
2. returns 3 storyboards. The first storyboard returns

         "url":"/api/v1/storyboards/UhbixyxgsiU?width=48&height=27",
         "templateUrl":"https://i.ytimg.com/sb/UhbixyxgsiU/storyboard3_L0/M$M.jpg?sqp=-oaymwENSDfyq4qpAwVwAcABBqLzl_8DBgjBmdybBg%3D%3D&sigh=rs%24AOn4CLCylqTadmdG47eeeabSoPONMNLC8g",
         "width":48,
         "height":27,
         "count":100,
         "interval":0,
         "storyboardWidth":10,
         "storyboardHeight":10,
         "storyboardCount":1

"interval":0 and link does not work

[SamantazFox]

Thanks for reporting :)

[ChunkyProgrammer]

This is what was done in FreeTube and may be adapted for Crystal (I'm not familiar with the storyboard parsing in the Invidious code base)
FreeTubeApp/FreeTube#3128

  const numberOfSubImagesPerImage = storyboard.columns * storyboard.rows
  // the number of storyboard images
  const numberOfImages = Math.ceil(storyboard.thumbnail_count / numberOfSubImagesPerImage)
let intervalInSeconds
  if (storyboard.interval > 0) {
    intervalInSeconds = storyboard.interval / 1000
  } else {
    intervalInSeconds = videoLengthSeconds / (numberOfImages * numberOfSubImagesPerImage)
  }