BUG/MINOR: stick-table: Use server_id instead of std_t_sint in process_store_rules()

Te commit 8c3cdf0a99 ("BUG/MAJOR: stick-tables: do not try to index a server
name for applets") was not properly backported. On HAProxy 2.4, the server
id have to be store in the server_id data type.

It is a 2.4-specific commit. Thus there is no upstream ID. No backport
needed.
diff --git a/src/stream.c b/src/stream.c
index f545c10..184866e 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -1457,7 +1457,7 @@
 
 		HA_RWLOCK_WRLOCK(STK_SESS_LOCK, &ts->lock);
 		ptr = __stktable_data_ptr(t, ts, STKTABLE_DT_SERVER_ID);
-		stktable_data_cast(ptr, std_t_sint) = __objt_server(s->target)->puid;
+		stktable_data_cast(ptr, server_id) = __objt_server(s->target)->puid;
 
 		if (key) {
 			de = dict_insert(&server_key_dict, key);