v2.4.4 update greenlock with latest security features

package.json

@@ -1,6 +1,6 @@
 {
   "name": "greenlock-express",
-  "version": "2.4.3",
+  "version": "2.4.4",
   "description": "Free SSL and managed or automatic HTTPS for node.js with Express, Koa, Connect, Hapi, and all other middleware systems.",
   "main": "index.js",
   "homepage": "https://git.coolaj86.com/coolaj86/greenlock-express.js",
@@ -8,7 +8,7 @@
     "example": "examples"
   },
   "dependencies": {
-    "greenlock": "^2.3.11",
+    "greenlock": "^2.4.1",
     "le-challenge-fs": "^2.0.8",
     "le-sni-auto": "^2.1.4",
     "le-store-certbot": "^2.1.0",