Improve XML signature detection (minor change); remove CHANGELOG

# Version 2.x

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

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

## 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

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

                   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. */

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

                try {

                try {

                    val firstBytes = ByteArray(5)

                    val firstBytes = ByteArray(XML_SIGNATURE.size)

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

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

                    if (XML_SIGNATURE.contentEquals(firstBytes)) {

                    if (XML_SIGNATURE.contentEquals(firstBytes)) {

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

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