Merge branch 'T13142-TasksMax' into 'collabora/master'

Added obsworker.service.d/tasks.conf to override DefaultTasksMax.

See merge request obs/open-build-service-debian!8

debian/obs-worker.install

+# systemd stuff
+debian/systemd/obsworker@.service	/lib/systemd/system/
+debian/systemd/obsworker.service.d/tasks.conf	/lib/systemd/obsworker.service.d/

debian/systemd/obsworker.service.d/tasks.conf

+[Service]
+TasksMax=64000