chore(release): publish

- netlify-cms-app@2.12.4
 - netlify-cms-backend-proxy@1.0.6
 - netlify-cms-core@2.23.4
 - netlify-cms-locales@1.10.3
 - netlify-cms-widget-file@2.6.4
 - netlify-cms@2.10.40

packages/netlify-cms/package.json

@@ -1,7 +1,7 @@
 {
   "name": "netlify-cms",
   "description": "An extensible, open source, Git-based, React CMS for static sites.",
-  "version": "2.10.39",
+  "version": "2.10.40",
   "homepage": "https://www.netlifycms.org",
   "repository": "https://github.com/netlify/netlify-cms",
   "bugs": "https://github.com/netlify/netlify-cms/issues",
@@ -21,7 +21,7 @@
   "license": "MIT",
   "dependencies": {
     "codemirror": "^5.46.0",
-    "netlify-cms-app": "^2.12.3",
+    "netlify-cms-app": "^2.12.4",
     "netlify-cms-media-library-cloudinary": "^1.3.4",
     "netlify-cms-media-library-uploadcare": "^0.5.5",
     "react": "^16.8.4",