meta-oe/static-ids: Change postgres to 28 to match forced id in recipe

Current recipe does impose UID=GID=28 in the recipe code.
Change postgres static ID to match in order to avoid a warning in
reproducibility tests.

Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/files/static-group-meta-oe

@@ -2,7 +2,7 @@ redis:x:600:
 xrdp:x:601:
 sanlock:x:602:
 mysql:x:603:
-postgres:x:604:
+postgres:x:28:
 zabbix:x:605:
 mail:x:606:
 nogroup:x:65534:

meta-oe/files/static-passwd-meta-oe

@@ -2,7 +2,7 @@ redis:x:600:600::/:/bin/nologin
 xrdp:x:601:601::/:/bin/nologin
 sanlock:x:602:602::/:/bin/nologin
 mysql:x:603:603::/:/bin/nologin
-postgres:x:604:604::/:/bin/nologin
+postgres:x:28:28::/:/bin/nologin
 zabbix:x:605:605::/:/bin/nologin
 cyrus:x:606:nogroup::/:/bin/nologin
 pcp:x:620:nogroup::/:/bin/nologin