[1.17.0-rc2] LDAP Failed authentication when user CN attribute contains escaped characters

[gd197]

Description

When using LDAP with BindDN authentication and configuring the auth source to grab user name from the CN attribute, if the user CN attribute is containing escaped characters (here coma ",") then the authentication fail
`
2022/07/20 11:03:05 ...dap/source_search.go:82:findUserDN() [T] [62d7c4c9] Search for LDAP user: axxxxxx
2022/07/20 11:03:05 ...dap/source_search.go:90:findUserDN() [T] [62d7c4c9] Searching for DN using filter (&(objectClass=user)(sAMAccountName=axxxxxx)) and base ou=PEOPLE,dc=MY,dc=COMPANY,dc=CORP
2022/07/20 11:03:05 ...dap/source_search.go:142:bindUser() [T] [62d7c4c9] Binding with userDN: CN=NAME, SURNAME,OU=Internal,OU=People,DC=my,DC=company,DC=corp
2022/07/20 11:03:05 ...dap/source_search.go:148:bindUser() [T] [62d7c4c9] Bound successfully with userDN: CN=NAME, SURNAME,OU=Internal,OU=People,DC=my,DC=company,DC=corp
2022/07/20 11:03:05 ...dap/source_search.go:353:SearchEntry() [T] [62d7c4c9] Fetching attributes 'cn', 'givenName', 'sn', 'mail', '', '', 'dn' with filter '(&(objectClass=user)(sAMAccountName=axxxxxx))' and base 'CN=NAME, SURNAME,OU=Internal,OU=People,DC=my,DC=company,DC=corp'
2022/07/20 11:03:05 ...dap/source_search.go:156:checkAdmin() [T] [62d7c4c9] Checking admin with filter (memberof=CN=adminusr,OU=ApplicationsManagement,DC=MY,DC=COMPANY,DC=CORP) and base CN=NAME, SURNAME,OU=Internal,OU=People,DC=my,DC=company,DC=corp
2022/07/20 11:03:05 ...vices/auth/signin.go:116:UserSignIn() [W] [62d7c4c9] Failed to login 'axxxx' via 'LDAP': User name is invalid [NAME, SURNAME]: must be valid alpha or numeric or dash(-_) or dot characters
2022/07/20 11:03:05 ...s/context/context.go:218:HTML() [D] [62d7c4c9] Template: user/auth/signin
2022/07/20 11:03:05 ...ers/web/auth/auth.go:200:SignInPost() [I] [62d7c4c9] Failed authentication attempt for axxxxxx from 152.30.1.53:0: user does not exist [uid: 0, name: axxxxxx, keyid: 0]

`
I Guess same issue as for #20181 and probably there since time but I never tested it until today
By removing the CN attribute in the username attribute field, then authentication works

Gitea Version

1.17.0-rc2

Can you reproduce the bug on the Gitea demo site?

No

Log Gist

No response

Screenshots

No response

Git Version

No response

Operating System

RHEL 7

How are you running Gitea?

Binary from the "release" tab on github

Database

MySQL