Fix a couple of harmless but annoying -Wundef warnings
These warnings appear when building the library with -Wundef, which is a useful warning option IME as it can catch typos in the macro names, even though it's not included in the usual -Wall.
The 17.0 major release is coming on May 16, 2024! This version brings many exciting improvements to GitLab, but also removes some deprecated features. We are introducing three breaking change windows during which we expect breaking changes to be deployed to GitLab.com. You can read more about it on our blogpost. The first breaking change window begins 2024-04-22 09:00UTC and ends 2024-04-24 22:00UTC.
These warnings appear when building the library with -Wundef, which is a useful warning option IME as it can catch typos in the macro names, even though it's not included in the usual -Wall.