This update for slurm_18_08 fixes the following issues:

- Fix Authentication Bypass when Message Aggregation is enabled CVE-2020-12693
This fixes and issue where authentication could be bypassed via an alternate
path or channel when message Aggregation was enabled.
A race condition allowed a user to launch a process as an arbitrary user.
(CVE-2020-12693, bsc#1172004).
Add: Fix-Authentication-Bypass-when-Message-Aggregation-is-enabled-CVE-2020-12693.patch
- Remove unneeded build dependency to postgresql-devel.