Allow using abstract namespace for crashtracker unix socket #594

Thanks to PrivateTmp in systemd it's pretty likely that different processes will see the same sidecar (which lives in a network namespace), but may not see the crashtracker socket in /tmp. Defaulting to the abstract unix namespace on Linux will work around any possible problems here. Signed-off-by: Bob Weinand <bob.weinand@datadoghq.com>

Signed-off-by: Bob Weinand <bob.weinand@datadoghq.com>

This reverts commit c7a60a6.