Unshlikht becomes Unschlicht in German transcription, and there is a notable namesake with this surname:
https://de.wikipedia.org/wiki/Josef_Unschlicht
(article in German).
Unschlicht can be analysed as a German adjective un-schlicht "not simple, not plain, not stupid". I don't know if there are specific Jewish connotations for the choice of this surname going beyond the simple German meaning. Unschlicht is a rare to obscure name in Germany, a phone book search gives zero hits, and GND authority control data have one the Josef Unschlicht mentioned above.