[master] d869640ba Steal stream 0 from its h2 session before releasing

[Dridi Boukelmoune]

commit d869640ba8b4978c890610a1a6dcd1bf82a600d3
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Fri Apr 19 10:31:15 2019 +0200

    Steal stream 0 from its h2 session before releasing

diff --git a/bin/varnishd/http2/cache_http2_session.c b/bin/varnishd/http2/cache_http2_session.c
index efd560db6..4fd379cd9 100644
--- a/bin/varnishd/http2/cache_http2_session.c
+++ b/bin/varnishd/http2/cache_http2_session.c
@@ -150,7 +150,7 @@ h2_del_sess(struct worker *wrk, struct h2_sess *h2, enum sess_close reason)
 
 	VHT_Fini(h2->dectbl);
 	AZ(pthread_cond_destroy(h2->winupd_cond));
-	req = h2->srq;
+	TAKE_OBJ_NOTNULL(req, &h2->srq, REQ_MAGIC);
 	AZ(req->ws->r);
 	sp = h2->sess;
 	Req_Cleanup(sp, wrk, req);