Use .js import for exifr in Thumbnail Generator (#2195)

Current build tools seem to have issues importing .cjs files

packages/@uppy/thumbnail-generator/src/index.js

@@ -4,7 +4,7 @@ const dataURItoBlob = require('@uppy/utils/lib/dataURItoBlob')
 const isObjectURL = require('@uppy/utils/lib/isObjectURL')
 const isPreviewSupported = require('@uppy/utils/lib/isPreviewSupported')
 const ORIENTATIONS = require('./image-orientations')
-const exifr = require('exifr/dist/mini.legacy.umd.cjs')
+const exifr = require('exifr/dist/mini.legacy.umd.js')
 
 /**
  * The Thumbnail Generator plugin