Fix old integrity hashes being added to the entrypoints.json with --watch

Author: Lyrkan

lib/plugins/entry-files-manifest.js

@@ -28,8 +28,10 @@ function processOutput(webpackConfig) {
         // the original assets (so, assets.entrypoints) + the new
         // assets (which will have their original structure). We
         // delete the entrypoints key, and then process the new assets
-        // like normal below
+        // like normal below. The same reasoning applies to the
+        // integrity key.
         delete assets.entrypoints;
+        delete assets.integrity;
 
         // This will iterate over all the entry points and convert the
         // one file entries into an array of one entry since that was how the entry point file was before this change.