portupgrade to openldap-server-2.3.23 seems to cause Undefined symbol "pthread_getconcurrency"

[eculp at bafirst.com]

I just did a portupgrade to openldap-server-2.3.23 but when starting 
slapd with debuging it would stop with the following error 
/libexec/ld-elf.so.1: /usr/local/lib/libldap_r-2.3.so.2: Undefined 
symbol "pthread_getconcurrency"

I reverted to openldap-server-2.3.21 and all is well again.

thanks,

ed