fix(gatsby-plugin-offline): use base path instead of path prefix (#17446)

* Set path resources on route update (for initial page load)

* use base path instead of path prefix

* fix min gatsby version

Author: vtenfys

packages/gatsby-plugin-offline/package.json

@@ -34,7 +34,7 @@
   "license": "MIT",
   "main": "index.js",
   "peerDependencies": {
-    "gatsby": "^2.0.100"
+    "gatsby": "^2.4.0"
   },
   "repository": {
     "type": "git",

packages/gatsby-plugin-offline/src/gatsby-browser.js

@@ -79,7 +79,7 @@ function setPathResources(path, getResourceURLsForPathname) {
 }
 
 exports.onRouteUpdate = ({ location, getResourceURLsForPathname }) => {
-  const pathname = location.pathname.replace(__PATH_PREFIX__, ``)
+  const pathname = location.pathname.replace(__BASE_PATH__, ``)
   setPathResources(pathname, getResourceURLsForPathname)
 }