[#146] Add kludge.bypass_content_encoding_check_in_chunks flag

Flag allows to skip checking `Content-Encoding` for `aws-chunked` value

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

api/headers.go

@@ -117,10 +117,6 @@ var SystemMetadata = map[string]struct{}{
 }
 
 func IsSignedStreamingV4(r *http.Request) bool {
-	// The Content-Encoding must have "aws-chunked" as part of its value.
-	// https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-streaming.html
-	// Minio does not set this value, thus for compatibility reasons
-	// we do not check it.
 	return r.Header.Get(AmzContentSha256) == StreamingContentSHA256 &&
 		r.Method == http.MethodPut
 }