fix IOPub parent checking in notebook

prevented 'dead kernel' messages from arriving.

IPython/frontend/html/notebook/static/js/notebook.js

@@ -766,9 +766,10 b' var IPython = (function (IPython) {'
         // console.log(reply);
         var msg_type = reply.header.msg_type;
         var cell = this.cell_for_msg(reply.parent_header.msg_id);
-        if (!cell){
-            // message not from this notebook
+        if (msg_type !== 'status' && !cell){
+            // message not from this notebook, but should be attached to a cell
             console.log("Received IOPub message not caused by one of my cells");
+            console.log(reply);
             return;
         }
         var output_types = ['stream','display_data','pyout','pyerr'];