tell OpenCppCoverage that we run an optimized build
should fix the crash accordign to the doc linked there
https://github.com/OpenCppCoverage/OpenCppCoverage/wiki/FAQ#your-application-has-thrown-an-unhandled-exception-code-3221225477-exception_access_violation
Signed-off-by: Matthieu Gallien <matthieu.gallien@nextcloud.com>