BUG #15495: Ldap authentication not working with multiple server in Postgresql 11

The following bug has been logged on the website:

Bug reference:      15495
Logged by:          Renaud Navarro
Email address:      rnavarro@nocibe.fr
PostgreSQL version: 11.1
Operating system:   Oracle Linux 7.5
Description:        

Hi

After upgrade database from postgresql 10.5 to postgresql 11.1, LDAP
authentication no longer work with multiple ldap server specified.
The pg_hba.conf have the following line :
hostssl    all             all             172.20.0.0/16           ldap
ldapserver="dcinfrap01s.nocibe.net dcinfrap02s.nocibe.net"
ldapprefix="NOCIBE\" ldaptls=1 "
I have the following error in log file :
2018-11-09 16:32:45.407 CET [29629] LOG:  could not initialize LDAP: Bad
parameter to an ldap routine
2018-11-09 16:32:45.408 CET [29629] FATAL:  LDAP authentication failed for
user "admin_rnavarro"
If I modify the pg_hba.conf with one LDAP server, the authentication is
working.
The same entry with postgresql 10.5 work perfectly

Thanks for helping me

Kind Regards