mp4 mux: do not advertise non mov files as QuickTime files

Fix AAC-LC playback with QT 10.3 (727.4)

(cherry picked from commit 08f8853b60ad68629b14aabea1595047ef7a3288)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/mux/mp4.c

@@ -210,7 +210,6 @@ static int Open(vlc_object_t *p_this)
         else
             bo_add_fourcc(box, "mp41");
         bo_add_fourcc(box, "avc1");
-        bo_add_fourcc(box, "qt  ");
         box_fix(box);
 
         p_sys->i_pos += box->len;