fix pubsub connection with old vfs

package.json

@@ -100,7 +100,7 @@
         "c9.ide.preview": "#5f5fff0185",
         "c9.ide.preview.browser": "#897177be7f",
         "c9.ide.preview.markdown": "#c3174d86e0",
-        "c9.ide.pubsub": "#0fba9708be",
+        "c9.ide.pubsub": "#99b7289040",
         "c9.ide.readonly": "#a4605830c4",
         "c9.ide.recentfiles": "#7c099abf40",
         "c9.ide.remote": "#301d2ab519",