BUG/MINOR: action: Don't check http capture rules when no id is defined

This is a regression in the commit 29730ba5 ("MINOR: action: Add a functions to
check http capture rules"). We must check the capture id only when an id is
defined.

This patch must be backported in 1.8.
diff --git a/src/proto_http.c b/src/proto_http.c
index 7dd0daf..f2152d6 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -12049,6 +12049,9 @@
  */
 int check_http_req_capture(struct act_rule *rule, struct proxy *px, char **err)
 {
+	if (rule->action_ptr != http_action_req_capture_by_id)
+		return 1;
+
 	if (rule->arg.capid.idx >= px->nb_req_cap) {
 		memprintf(err, "unable to find capture id '%d' referenced by http-request capture rule",
 			  rule->arg.capid.idx);
@@ -12235,6 +12238,9 @@
  */
 int check_http_res_capture(struct act_rule *rule, struct proxy *px, char **err)
 {
+	if (rule->action_ptr != http_action_res_capture_by_id)
+		return 1;
+
 	if (rule->arg.capid.idx >= px->nb_rsp_cap) {
 		memprintf(err, "unable to find capture id '%d' referenced by http-response capture rule",
 			  rule->arg.capid.idx);