remove unneeded querystring dep

Author: feross

package.json

@@ -25,7 +25,6 @@
     "inherits": "^2.0.1",
     "ip": "^0.3.0",
     "once": "^1.3.0",
-    "querystring": "^0.2.0",
     "run-parallel": "^1.0.0",
     "string2compact": "^1.1.1"
   },