BUG/MEDIUM: streams: Make sur SI_FL_L7_RETRY is set before attempting a retry.

In a few cases, we'd just check if the backend is configured to do retries,
and not if it's still allowed on the stream_interface.
The SI_FL_L7_RETRY flag could have been removed because we failed to allocate
a buffer, or because the request was too big to fit in a single buffer,
so make sure it's there before attempting a retry.
diff --git a/src/proto_htx.c b/src/proto_htx.c
index b99b9cf..e7341c1 100644
--- a/src/proto_htx.c
+++ b/src/proto_htx.c
@@ -1528,6 +1528,7 @@
 			 */
 			if (conn->err_code == CO_ER_SSL_EARLY_FAILED) {
 				if ((s->be->retry_type & PR_RE_EARLY_ERROR) &&
+				    (si_b->flags & SI_FL_L7_RETRY) &&
 				    do_l7_retry(s, si_b) == 0)
 					return 0;
 				txn->status = 425;
@@ -1817,6 +1818,7 @@
 		health_adjust(__objt_server(s->target), HANA_STATUS_HTTP_HDRRSP);
 	}
 	if ((s->be->retry_type & PR_RE_JUNK_REQUEST) &&
+	    (si_b->flags & SI_FL_L7_RETRY) &&
 	    do_l7_retry(s, si_b) == 0)
 		return 0;
 	txn->status = 502;