[PATCH] imap-login: Fix excessive memory growth with pre-login ID command

[PATCH] imap-login: Fix excessive memory growth with pre-login ID command

The pre-login ID parser reset the per-argument line and list limits after
every argument, so nothing bounded the number of key/value pairs. Each
external key grew log_reply and added a distinct event field (a linear
scan, making it O(N^2)), allowing a pre-auth CPU/memory amplification.

Account at most 30 pairs (per RFC 2971) into the logging and client_id
bookkeeping. Internal x-* parameter handlers still run for pairs beyond
the limit, since a trusted proxy may legitimately forward more fields.

Gbp-Pq: Name 0001-imap-login-Fix-excessive-memory-growth-with-pre-logi.patch