feat: Contact::lookup_id_by_addr_ex: Prefer returning key-contact

If an address-contact and a key-contact were seen at exactly the same time, that doesn't necessarily
mean that it's a random event, it might occur because some code updates contacts this way in some
scenario. While this is unlikely, prefer to look up the key-contact.

src/contact.rs

@@ -808,7 +808,7 @@ impl Contact {
                 "SELECT id FROM contacts
                  WHERE addr=?1 COLLATE NOCASE
                  AND id>?2 AND origin>=?3 AND (? OR blocked=?)
-                 ORDER BY last_seen DESC LIMIT 1",
+                 ORDER BY last_seen DESC, fingerprint DESC LIMIT 1",
                 (
                     &addr_normalized,
                     ContactId::LAST_SPECIAL,