Issue 50431 - Fix regression from coverity fix
Description: Fix a regression from the initial coverity commit
where we did not allow NULL pointers to set into
the pblock. They were false positives reported by
covscan.
https://pagure.io/389-ds-base/issue/50431
Reviewed by: mreynolds (one line commit rule)
(cherry picked from commit 054d32e7b697513124a37dade54828ec52397c1c)