Fix of codec debug message.

src/http/modules/ngx_http_mp4_module.c

diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
index 2275dbf..1f08082 100644
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -1693,7 +1693,9 @@
 
         ngx_log_debug3(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
                        "stsd entries:%ui, codec:%*s",
-                       entries, 4, atom_table);
+                       entries, 4,
+                       atom_header + sizeof(ngx_mp4_stsd_atom_t) + 4);
+
     }
     }
 #endif