📝 docs: librechat.example.yaml (#6442)

Correctly comment commented comments:
```
```
to
```
```

To allow for simple removal of the 1st level comments.

.env.example

@@ -441,7 +441,7 @@ LDAP_URL=
 LDAP_BIND_DN=
 LDAP_BIND_CREDENTIALS=
 LDAP_USER_SEARCH_BASE=
-LDAP_SEARCH_FILTER=mail={{username}}
+#LDAP_SEARCH_FILTER="mail="
 LDAP_CA_CERT_PATH=
 # LDAP_TLS_REJECT_UNAUTHORIZED=
 # LDAP_STARTTLS=