Tune download (#2)

* s2-2

* allowedPrivateNetworks

* style

* Proxyの間にあると誤解しそうなのでconfigの記述順を変更

* Fix error handler

package.json

@@ -148,6 +148,7 @@
 		"http-signature": "1.3.5",
 		"idb-keyval": "5.1.3",
 		"insert-text-at-cursor": "0.3.0",
+		"ip-cidr": "3.0.4",
 		"is-svg": "4.3.1",
 		"js-yaml": "4.1.0",
 		"jsdom": "16.7.0",
@@ -184,6 +185,7 @@
 		"postcss": "8.3.6",
 		"postcss-loader": "6.1.1",
 		"prismjs": "1.24.1",
+		"private-ip": "2.2.1",
 		"probe-image-size": "7.2.1",
 		"promise-limit": "2.7.0",
 		"pug": "3.0.2",