Add debug info for unassigned token

[rlevytskyi]

Hi Cornelius,

While working with reassign-tokens.py script, I noticed it sometimes produces an error like this (on unassigned token):

Token TOTP00716C3B assigned to rlevytskyi@exadel.com will be migrated to resolver keycloak5 in realm exadel.com.
 +-- Assigned token TOTP00716C3B to user <rlevytskyi.keycloak5@exadel.com>.
Traceback (most recent call last):
  File "/opt/privacyidea/./reassign-tokens.py", line 63, in <module>
    serial, tok.user.login, from_realm, to_resolver, to_realm
            ^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'login'

With this traceback, it is unclear that error is not about 6C3B token but about next token.

I've added a line to print token-to-be-checked so user has a clue of the failed token, like this:

Checking token TOTP00716C3B ...
Token TOTP00716C3B assigned to rlevytskyi@exadel.com will be migrated to resolver keycloak5 in realm exadel.com.
 +-- Assigned token TOTP00716C3B to user <rlevytskyi.keycloak5@exadel.com>.
Checking token TOTP00720AF2 ...
Traceback (most recent call last):
  File "/opt/privacyidea/./reassign-tokens.py", line 63, in <module>
    serial, tok.user.login, from_realm, to_resolver, to_realm
            ^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'login'

With this output, it is clear that token in the traceback is 0AF2.

Here's my patch:

--- reassign-tokens.py.old	2026-05-26 16:01:28.946359072 +0300
+++ reassign-tokens.py	2026-05-26 16:02:26.578908310 +0300
@@ -58,6 +58,7 @@
     toks = get_tokens(realm=from_realm, resolver=from_resolver)
     for tok in toks:
         serial = tok.token.serial
+        print("Checking token {0!s} ...".format( serial))
         print("Token {0!s} assigned to {1!s}@{2!s} will be migrated to resolver {3!s} in realm {4!s}.".format(
             serial, tok.user.login, from_realm, to_resolver, to_realm
         ))