Atomic enforces usage of its only safe constructor,
in contrast to std::atomic.
"The default-initialized std::atomic<T> does not contain
a T object, and its only valid uses are destruction and
initialization by std::atomic_init, see LWG issue 2334."
-- https://en.cppreference.com/w/cpp/atomic/atomic/atomic
To prevent Icinga2 from being restarted while
one or more requests are still in progress and end up
as corrupted stages without status file and startup logs.
What does this change?
* Remove use of spaces for formatting
These could be found by using `grep -r -l -P '^\t+ +[^*]'
* Removal of training whitespaces
* A few lines longer than 120 chars
