message: fixed mimetype for .mp4
diff: @@ -37,7 +37,7 @@ export const mimes = new Map([
  [".jpeg", "image/jpg"],
  [".gif", "image/gif"],
  [".mp3", "audio/mpeg"],
  - [".mp4", "video/mpeg"],
  + [".mp4", "video/mp4"],
  [".xml", "text/xml"],
  [".woff", "font/woff"],
  [".woff2", "font/woff2"],
  