I believe the question I was answering was originally about a different file. Anyway, it seems the question was “dropped”.
Yes, because I realized I was looking at the wrong files.
I filed an actual issue about it (resolver: Possibly redundant DHCP script for setting DHCP clients in DNS in init script (#378) · Issues · Turris / Turris OS / Turris Build · GitLab). I agree with @vcunat that it might be harmless in the default configuration, although it does produce quite a noise in the logs.