fix +6546: Add Alt-Shift-T to reopen the last closed tab

package.json

@@ -73,7 +73,7 @@
         "c9.ide.ace.split": "#0ae0151c78",
         "c9.ide.ace.statusbar": "#d7b45bb7c3",
         "c9.ide.ace.stripws": "#34426a03d1",
-        "c9.ide.behaviors": "#3dbcad4203",
+        "c9.ide.behaviors": "#6aad7006a0",
         "c9.ide.closeconfirmation": "#a28bfd8272",
         "c9.ide.configuration": "#b8470f4107",
         "c9.ide.dialog.wizard": "#a588b64050",