attached patch proposes solution for leaking memory when non-existing netgroup is looked
1st patch is just for testing - just call 'pkill -SIGUSR1 sssd_nss' and talloc
report will be generated in /tmp/sssd_nss_talloc_report_full.
For details about the bug please see commit message in 2nd patch.
User who reported the bug confirmed that so far it seems that memory leak has been fixed
and he didn't report any side effects.