Fixing #1348 to allow Ctrl-M M to work w/o releasing Ctrl.

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

@@ -95,7 +95,7 b' var IPython = (function (IPython) {'
             } else if (event.which === 13 && event.ctrlKey) {
                 that.execute_selected_cell({terminal:true});
                 return false;
-            } else if (event.which === 77 && event.ctrlKey) {
+            } else if (event.which === 77 && event.ctrlKey && that.control_key_active == false) {
                 that.control_key_active = true;
                 return false;
             } else if (event.which === 88 && that.control_key_active) {