Remove json-loader, unnecessary with Webpack v2

See these notes:

- https://webpack.js.org/guides/migrating/#json-loader-is-not-required-anymore
- https://github.com/webpack-contrib/json-loader#json-loader

package.json

@@ -49,7 +49,6 @@
     "express-handlebars": "3.0.0",
     "fs-extra": "2.1.2",
     "irc-framework": "2.8.0",
-    "json-loader": "0.5.4",
     "ldapjs": "1.0.1",
     "lodash": "4.17.4",
     "moment": "2.18.1",

webpack.config.js

@@ -47,10 +47,6 @@ let config = {
 					}
 				}
 			},
-			{
-				test: /\.json$/,
-				loader: "json-loader"
-			},
 			{
 				test: /\.tpl$/,
 				include: [