Update vm

Author: DD Liu

package.json

@@ -113,7 +113,7 @@
     "scratch-render": "0.1.0-prerelease.20190819154958",
     "scratch-storage": "1.3.2",
     "scratch-svg-renderer": "0.2.0-prerelease.20190820171249",
-    "scratch-vm": "0.2.0-prerelease.20190813192748",
+    "scratch-vm": "0.2.0-prerelease.20190822194548",
     "selenium-webdriver": "3.6.0",
     "startaudiocontext": "1.2.1",
     "style-loader": "^0.23.0",