[bugfix] Fix macro guard in overlappingschwarztest

The loaction of the macro guard lead to the method test not returning a value if neiter SUperLU nore SuiteSparse are found. While the test is not executed in this case due to a CMake guard, these macro guards should be placed in the correct place anyways for reasons of code hygiene.

enabled an automatic merge when the pipeline for 62b6707e succeeds

merged

mentioned in commit 56181a79

The CI for master failed after merging due to a 'no space left on device' error. @ansgar: Can you have a look?

@carsten.graeser: The gitlab-runner-docker-cleanup tool doesn't clean up volumes used by the cache.

I now disabled the cache feature by setting disable_cache = true in gitlab-runner's config.toml.