MINOR: stream_interface: add a client target : TARG_TYPE_CLIENT

This one will be used to identify the direction the SI is being used. All
incoming connections have a target of type TARG_TYPE_CLIENT.
diff --git a/src/peers.c b/src/peers.c
index a3408f5..6d84b4e 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1157,7 +1157,7 @@
 	s->si[0].proto   = NULL;
 	s->si[0].release = NULL;
 	s->si[0].send_proxy_ofs = 0;
-	clear_target(&s->si[0].target);
+	set_target_client(&s->si[0].target);
 	s->si[0].exp = TICK_ETERNITY;
 	s->si[0].flags = SI_FL_NONE;
 	if (s->fe->options2 & PR_O2_INDEPSTR)