Ensure userAgent is always of type string

Update DeviceDetector.php

prepare 4.2.2

prepare 4.2.1

update README.md (matomo-org#6688)

Co-authored-by: sgiehl <[email protected]>

Merge pull request matomo-org#6572 from matomo-org/updatereadme

Update README.md

bump version number

bump version number

update package name

new release