Backport a fix for CommonsMetadata
completed by: ☃ unicodesnowman
mentors: Gergő Tisza
Task T86032 in Wikimedia's issue tracker describes a small problem which was fixed but still exists in the 1.23 version (branch REL1_23). Backport the fix, verify nothing is broken (running the unit tests should be enough) and submit the patch to the 1.23 branch. See this tutorial.
Students are required to read Wikimedia's general instructions first.