cleanup: cleanup of unreachable code

Either we would have bound the connection thanks to auto_bind, or we
would have had an unhandled error. Due to this, we can remove this.

ldapauthenticator/ldapauthenticator.py

@@ -335,11 +335,6 @@ def resolve_username(self, username_supplied_by_user):
             userdn=self.lookup_dn_search_user,
             password=self.lookup_dn_search_password,
         )
-        if not conn.bind():
-            self.log.warning(
-                f"Failed to connect to LDAP server with search user '{self.lookup_dn_search_user}'"
-            )
-            return (None, None)
 
         search_filter = self.lookup_dn_search_filter.format(
             login_attr=self.user_attribute,