LDAP auth login not working netbox 2.7.4

[fmax]

we are using LDAP auth.
config file /opt/netbox/netbox/ldap_config.py got copied from 2.7.1 version before.

Environment

• Python version: 3.6.8
• NetBox version: 2.7.4

Steps to Reproduce

update from v2.7.1 to v2.7.4

1. follow update option A: https://netbox.readthedocs.io/en/stable/installation/upgrading/
2. ./upgrade.sh ran successfully
3. restarted netbox and netbox-rqworker

Expected Behavior

login in netbox installation after update procedure

Observed Behavior

cannot login in netbox web-ui
Errors
Please enter a correct username and password. Note that both fields may be case-sensitive.

[DanSheps]

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