Improve device identifier string (#2142)
Improve device identifier string (#2142)

See https://github.com/openhab/openhab-android/pull/2136#pullrequestreview-464926327

Signed-off-by: mueller-ma <fac07b9175991ebb2e15926da5ff5c758acad074@users.noreply.github.com>
openhab/openhab.android