Remove local settings from webpack config

Despite the explicit note I left for myself to remove local settings
from the webpack dev config in PR https://github.com/Ensembl/ensembl-client/pull/478,
I forgot to. Silly me.

src/ensembl/webpack/environments/webpack.config.dev.js

@@ -47,17 +47,10 @@ const devServerConfig = {
    */
   proxy: [
     {
-      context: ['/api/**', '!/api/docs/**'],
+      context: ['/api/**'],
       target: 'https://staging-2020.ensembl.org',
       changeOrigin: true,
       secure: false
-    },
-    {
-      context: ['/api/docs'],
-      target: 'http://localhost:3000',
-      pathRewrite: { '^/api/docs': '/api' },
-      changeOrigin: true,
-      secure: false
     }
   ],