MINOR: muxes: Don't bother to LIST_DEL(&conn->list) before calling conn_free().

conn_free() already removes the connection from any idle list, so there's no
need to do it in the mux code, just before calling conn_free().
diff --git a/src/mux_h1.c b/src/mux_h1.c
index ead67e0..3fe6f95 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -443,8 +443,6 @@
 {
 	struct h1c *h1c = conn->ctx;
 
-	LIST_DEL(&conn->list);
-
 	if (h1c) {
 		if (!LIST_ISEMPTY(&h1c->buf_wait.list)) {
 			HA_SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
diff --git a/src/mux_h2.c b/src/mux_h2.c
index fabbe1c..5fdaadf 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -600,8 +600,6 @@
 {
 	struct h2c *h2c = conn->ctx;
 
-	LIST_DEL(&conn->list);
-
 	if (h2c) {
 		hpack_dht_free(h2c->ddht);
 
diff --git a/src/mux_pt.c b/src/mux_pt.c
index 462a759..4f53920 100644
--- a/src/mux_pt.c
+++ b/src/mux_pt.c
@@ -28,7 +28,6 @@
 {
 	struct connection *conn = ctx->conn;
 
-	LIST_DEL(&conn->list);
 	conn_stop_tracking(conn);
 	conn_full_close(conn);
 	tasklet_free(ctx->wait_event.task);