MINOR: stream-int/conn-stream: Report error to the CS instead of the SI

SI_FL_ERR is removed and replaced by CS_FL_ERROR. It is a transient patch
because the idea is to rely on the endpoint to handle errors at this
level. But if for any reason it is not possible, the stream-interface flags
will still be replaced.
diff --git a/src/http_ana.c b/src/http_ana.c
index f87db34..927f0b9 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -1247,8 +1247,9 @@
 	req->flags &= ~(CF_WRITE_ERROR | CF_WRITE_TIMEOUT | CF_SHUTW | CF_SHUTW_NOW);
 	res->flags &= ~(CF_READ_ERROR | CF_READ_TIMEOUT | CF_SHUTR | CF_EOI | CF_READ_NULL | CF_SHUTR_NOW);
 	res->analysers &= AN_RES_FLT_END;
-	si->flags &= ~(SI_FL_ERR | SI_FL_RXBLK_SHUT);
+	si->flags &= ~SI_FL_RXBLK_SHUT;
 	si->err_type = SI_ET_NONE;
+	si->cs->flags &= ~CS_FL_ERR;
 	s->flags &= ~(SF_CONN_EXP | SF_ERR_MASK | SF_FINST_MASK);
 	s->conn_exp = TICK_ETERNITY;
 	stream_choose_redispatch(s);