lmdb typo in error log notice message

[jchapma]

Issue Description
Typo in the NOTICE message generated when a user sets mdb max readers

Package Version and Platform:

• Package and version: main branch

Steps to Reproduce

1. Set number of mdb max readers

sudo dsconf ldapi://%2fvar%2frun%2fslapd-inst01.socket backend config set --mdb-max-readers 123

2. See notice message in the error logs

[snip] - NOTICE - dbmdb_ctx_t_db_max_dbs_set - New nsslapd-mdb-max-dbs will not take affect until the server is restarted