Confusing WARN vs. ERROR for obsoleted packages

[mtelka]

The same message is used for both WARN and ERROR without clear distinction why it is once marked as WARN and then as ERROR:

$ target/release/oi-pkg-checker print-problems | grep 'obsoleted package.*runtime' | head
[WARN] obsoleted package library/python/webob-37 is required by package library/python/wsgiproxy2-37 (runtime, require)
[ERROR] obsoleted package developer/java/openjdk7 is required by package developer/groovy-24 (runtime, require)
[ERROR] obsoleted package library/python/asttokens-37 is required by package library/python/icecream-37 (runtime, require)
[ERROR] obsoleted package library/python/attrs-37 is required by package library/python/cmd2-37 (runtime, require)
[ERROR] obsoleted package library/python/attrs-37 is required by package library/python/automat-37 (runtime, require)
[ERROR] obsoleted package library/python/attrs-37 is required by package library/python/pytest-mypy-37 (runtime, require)
[ERROR] obsoleted package library/python/build-37 is required by package library/python/pyroma-37 (runtime, require)
[ERROR] obsoleted package library/python/build-37 is required by package library/python/check-manifest-37 (runtime, require)
[ERROR] obsoleted package library/python/click-37 is required by package library/python/lingua-37 (runtime, require)
[ERROR] obsoleted package library/python/coverage-37 is required by package library/python/codecov-37 (runtime, require)
$

I think the difference is that for the WARN case there still exists an older non-obsoleted package while for the ERROR case there is is no such non-obsoleted package available. If that's the case, could you please adjust messages to make it more obvious what's the difference between WARN and ERROR?

Thank you.