chore(package): update scratch-paint to version 0.2.0-prerelease.20190923154429

Closes #5201

package.json

@@ -109,7 +109,7 @@
     "scratch-audio": "0.1.0-prerelease.20190114210212",
     "scratch-l10n": "3.5.20190917223712",
     "scratch-blocks": "0.1.0-prerelease.1568071968",
-    "scratch-paint": "0.2.0-prerelease.20190822205009",
+    "scratch-paint": "0.2.0-prerelease.20190923154429",
     "scratch-render": "0.1.0-prerelease.20190912174749",
     "scratch-storage": "1.3.2",
     "scratch-svg-renderer": "0.2.0-prerelease.20190822202608",