This is a workaround for the build failure with mingw-w64 due to `UNIQUE_NAME` being defined in nb30.h https://github.com/mingw-w64/mingw-w64/blob/7f54c78e35c2056a6d972261d70e8ba8fbf1191a/mingw-w64-headers/include/nb30.h#L78
The conflict happens in a win64 build with `-DBUILD_BITCOIN_CHRONIK=ON`