title: zip file corrupted after uploading to AWS S3
body: <p>I upload my zip simply by Using <code>boto3</code> . Everything work fine except when I download the zip from my s3 bucket. When I'm trying to unzip in mac OS I get an <code>error 22</code> that let me know the zip cannot be uncompressed. I have no idea what's going wrong.</p>
  <p>Current situation :</p>
  <pre><code>file = request.files[&quot;my_zip_file&quot;] # file obj (multipart / form-data)
  s3.upload_fileobj(
                          file,
                          BUCKET_NAME,
                          folder_name,
                          ExtraArgs={
                             &quot;ContentEncoding&quot;: &quot;base64&quot;,
                             &quot;ContentType&quot;: file.content_type
                          }
                      )
  </code></pre>
  <p>Any suggestion ?</p>