message: fix constness
diff: @@ -104,7 +104,7 @@ export function decryptFile(file) {
  // they introduce XSS attacks if the Blob URI is viewed directly in the
  // browser (e.g. by copying the URI into a new tab or window.)
  // See warning at top of file.
  - const mimetype = file.mimetype ? file.mimetype.split(";")[0].trim() : '';
  + let mimetype = file.mimetype ? file.mimetype.split(";")[0].trim() : '';
  if (!ALLOWED_BLOB_MIMETYPES[mimetype]) {
  mimetype = 'application/octet-stream';
  }
  