[PATCH] Issue 4711 - SIGSEV with sync_repl (#4738)

[PATCH] Issue 4711 - SIGSEV with sync_repl (#4738)

Bug description:
	sync_repl sends back entries identified with a unique
	identifier that is 'nsuniqueid'. If 'nsuniqueid' is
	missing, then it may crash

Fix description:
	Check a nsuniqueid is available else returns OP_ERR

relates: https://github.com/389ds/389-ds-base/issues/4711

Reviewed by: Pierre Rogier, James Chapman, William Brown (Thanks!)

Platforms tested:  F33

Gbp-Pq: Name 4711-SIGSEV-with-sync_repl-4738.patch