There was a fallout when skipping concating these files to the
default ones (PR #1708). We should also have deactivated creating
these files at all. As a result these files appeared in all parallel
runs that were aborted.
This change now prevents creating and logging to these files in
parallel in a default
run (--enable-parallel-logging-fallout-warning=false).
Developers can still activate logging and concating to see whether
everything is only logged on the io process by passing
--enable-parallel-logging-fallout-warning=true.
Closes 3725