Added givenPortOnly user option

Allows user to disable gamedig's default behavior of adding query attempts using the default query port(-offset)

README.md

@@ -43,6 +43,7 @@ this query port may work instead. (defaults to protocol default port)
  will cause many queries to take longer even if the server is online. (default 2000)
 * **attemptTimeout**: number - Milliseconds allowed for an entire query attempt. This timeout is not commonly hit,
  as the socketTimeout typically fires first. (default 10000)
+* **givenPortOnly**: boolean - Only attempt to query server on given port. (default false)
 * **debug**: boolean - Enables massive amounts of debug logging to stdout. (default false)
 
 ### Return Value

bin/gamedig.js

@@ -4,13 +4,15 @@ const Minimist = require('minimist'),
     Gamedig = require('..');
 
 const argv = Minimist(process.argv.slice(2), {
-    boolean: ['pretty','debug']
+    boolean: ['pretty','debug','givenPortOnly']
 });
 
 const debug = argv.debug;
 delete argv.debug;
 const pretty = !!argv.pretty || debug;
 delete argv.pretty;
+const givenPortOnly = argv.givenPortOnly;
+delete argv.givenPortOnly;
 
 const options = {};
 for(const key of Object.keys(argv)) {
@@ -34,6 +36,9 @@ if (argv._.length >= 1) {
 if (debug) {
     options.debug = true;
 }
+if (givenPortOnly) {
+    options.givenPortOnly = true;
+}
 
 Gamedig.query(options)
     .then((state) => {

lib/QueryRunner.js

@@ -30,7 +30,7 @@ class QueryRunner {
         const attempts = [];
 
         if (userOptions.port) {
-            if (gameQueryPortOffset) {
+            if (gameQueryPortOffset && !userOptions.givenPortOnly) {
                 attempts.push({
                     ...defaultOptions,
                     ...gameOptions,
@@ -38,7 +38,7 @@ class QueryRunner {
                     port: userOptions.port + gameQueryPortOffset
                 });
             }
-            if (userOptions.port === gameOptions.port && gameQueryPort) {
+            if (userOptions.port === gameOptions.port && gameQueryPort && !userOptions.givenPortOnly) {
                 attempts.push({
                     ...defaultOptions,
                     ...gameOptions,