CLEANUP: stream: remove a useless call to si_detach()

It's pointless to call si_detach() after si_reset() since it does
nothing due to si->end being NULL.
diff --git a/src/stream.c b/src/stream.c
index 0cd5bb6..d7b8e9f 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -160,7 +160,6 @@
 	 * callbacks will be initialized before attempting to connect.
 	 */
 	si_reset(&s->si[1]);
-	si_detach(&s->si[1]);
 
 	if (likely(sess->fe->options2 & PR_O2_INDEPSTR))
 		s->si[1].flags |= SI_FL_INDEP_STR;