We need to reference repo1.maven.org in org.ops4j.pax.url.mvn.repositories using https rather than http.

In etc/org.ops4j.pax.url.mvn.cfg we currently have

org.ops4j.pax.url.mvn.repositories= \
    http://repo1.maven.org/maven2@id=maven.central.repo, \

but that repository does not allow plain http traffic anymore. We need to switch to https: instead.