Bump gatsby-plugin-netlify from 2.3.12 to 2.3.13

Bumps [gatsby-plugin-netlify](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-netlify) from 2.3.12 to 2.3.13.
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-netlify/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-plugin-netlify@2.3.13/packages/gatsby-plugin-netlify)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -18,7 +18,7 @@
     "gatsby-image": "^2.4.14",
     "gatsby-plugin-feed": "^2.5.11",
     "gatsby-plugin-local-search": "^1.1.1",
-    "gatsby-plugin-netlify": "^2.3.12",
+    "gatsby-plugin-netlify": "^2.3.13",
     "gatsby-plugin-react-helmet": "^3.3.10",
     "gatsby-plugin-sharp": "^2.6.25",
     "gatsby-remark-autolink-headers": "^2.3.11",