grml-keyring vs. grml-live usage of /etc/apt/sources.list.d/grml.sources

[mika]

See https://github.com/grml/grml-live/pull/424 - we would like to use grml.sources from grml-keyring package instead of duplicating it inside grml-live as config/files/GRMLBASE/etc/apt/sources.list.d/grml.sources (see https://github.com/grml/grml-live/blob/b87f78ce7d683c530c91d9244a8164f3e38cbc3f/config/files/GRMLBASE/etc/apt/sources.list.d/grml.sources).

See whether usage of a symlink inside grml-live which points to /usr/share/grml-keyring/grml.sources could do the job.