Remove undescore

A 50 kb library is not needed to make a function run once, especially
not when it doesn't work.  _.once does not modify the function passed to
it to only run once it returns a new function that only runs once.
Since the result of once was discarded, it had no effect.

Remove underscore and implement instanceManagement running once properly
with 3 lines of code.

client.js

@@ -8,7 +8,6 @@ const syncRequest = require('sync-request');
 const request = require("request");
 const ncp = require('ncp').ncp;
 const Rcon = require('rcon-client-fork').Rcon;
-const _ = require('underscore');
 const deepmerge = require("deepmerge");
 const getMac = require('getmac').getMac;
 const rmdirSync = require('rmdir-sync');
@@ -563,8 +562,11 @@ write-data=${ path.resolve(config.instanceDirectory, instance) }\r\n
 }
 
 // ensure instancemanagement only ever runs once
-_.once(instanceManagement);
+var _instanceInitialized;
 async function instanceManagement(instanceconfig) {
+	if (_instanceInitialized) return;
+	_instanceInitialized = true;
+
     console.log("Started instanceManagement();");
 
     /* Open websocket connection to master */

package.json

@@ -63,8 +63,7 @@
     "socket.io-prometheus": "^0.2.1",
     "sync-request": "^4.0.1",
     "tail": "^2.0.2",
-    "typescript-collections": "^1.3.2",
-    "underscore": "^1.8.3"
+    "typescript-collections": "^1.3.2"
   },
   "devDependencies": {
     "html5-validator": "^1.0.7",