Shared dashboard: fix "No user_id" error on access

GetUserMessagesTokenAuthPage called get_gui_messages() without a
user_id, causing it to fall back to user.ident which crashes since
there is no logged-in user in a token-auth context. Pass
token.issuer as the user_id directly.

JIRA-Ref: CMK-31393
Change-Id: I9510a0f42ccbd4b278e77442d05d4831a10d60c6

Author: smeagol91

cmk/gui/user_message/user_message.py

@@ -281,4 +281,6 @@ def ident(cls) -> str:
     def _post(
         self, token: AuthToken, token_details: DashboardToken, ctx: PageContext
     ) -> PageResult:
-        return sorted(message.get_gui_messages(), key=lambda e: e["time"], reverse=True)
+        return sorted(
+            message.get_gui_messages(user_id=token.issuer), key=lambda e: e["time"], reverse=True
+        )