fix(starters): update gatsby monorepo (#14754)

Author: renovate[bot]

starters/blog/package-lock.json

@@ -8,14 +8,14 @@
     "url": "https://github.com/gatsbyjs/gatsby/issues"
   },
   "dependencies": {
-    "gatsby": "^2.9.1",
-    "gatsby-image": "^2.1.3",
+    "gatsby": "^2.9.2",
+    "gatsby-image": "^2.1.4",
     "gatsby-plugin-feed": "^2.2.3",
     "gatsby-plugin-google-analytics": "^2.0.21",
     "gatsby-plugin-manifest": "^2.1.1",
-    "gatsby-plugin-offline": "^2.1.1",
+    "gatsby-plugin-offline": "^2.1.2",
     "gatsby-plugin-react-helmet": "^3.0.12",
-    "gatsby-plugin-sharp": "^2.1.4",
+    "gatsby-plugin-sharp": "^2.1.5",
     "gatsby-plugin-typography": "^2.2.13",
     "gatsby-remark-copy-linked-files": "^2.0.13",
     "gatsby-remark-images": "^3.0.14",