Improve XML signature detection (minor change); remove CHANGELOG

# Version 2.x

## Version 2.1.3

- keep own repo (built by Gitlab CI)

## Version 2.1.2

- add DAV:owner

- fix date parsing bug

## Version 2.1.1

- add ScheduleTag

- use okhttp 4.7.2

## Version 2.1

- don't rely on ServiceLoader anymore

## Version 2.0

- now uses okhttp 4.5.0, which requires Android 5

- removed deprecated methods

If you need support for older Android versions, stay with 1.x.

# Version 1.x

## Version 1.0.1

- `UrlUtils.equals()`: ignore #fragment URL parts

- updated dependencies

See https://github.com/bitfireAT/dav4jvm/compare/, for instance

https://github.com/bitfireAT/dav4jvm/compare/2.1.2...2.1.3

                   Some broken servers return an XML response with some other MIME type. So we try to see

                   whether the response is maybe XML although the Content-Type is something else. */

                try {

                    val firstBytes = ByteArray(5)

                    body.source().peek().read(firstBytes)

                    val firstBytes = ByteArray(XML_SIGNATURE.size)

                    body.source().peek().readFully(firstBytes)

                    if (XML_SIGNATURE.contentEquals(firstBytes)) {

                        Dav4jvm.log.warning("Received 207 Multi-Status that seems to be XML but has MIME type $mimeType")