fix for failed download with no subtitles when requested

Cleanup, traverse the list of args backwards, match all possible languages, regex in global var

lib/youtube-dl.js

@@ -17,10 +17,26 @@ fs.exists(file, function(exists) {
 });
 
 var isYouTubeRegex = /^(https?:\/\/)?(www\.)?(youtube\.com|youtu\.be)\//;
+var isNoSubsRegex = /WARNING: video doesn't have subtitles/;
+var subs = ['--write-sub', '--write-srt', '--srt-lang', '--all-subs'];
 
 // Check if win.
 var isWin = /^win/.test(process.platform);
 
+/**
+ * Regular Expresion IndexOf for Arrays
+ *
+ * @param {Array.<String>} arr
+ * @param {String} rx
+ */
+function reIndexOf(arr, rx) {
+    var i;
+    for (i in arr) {
+        if (arr[i].toString().match(rx)) { return i; }
+    }
+    return -1;
+}
+
 /**
  * Downloads a video.
  *
@@ -71,7 +87,6 @@ var ytdl = module.exports = function(url, args, options) {
  * @param {Function(!Error, String)} callback
  */
 function call(video, args1, args2, options, callback) {
-
   var args = args1.concat(util.parseOpts(args2));
 
   // Parse url.
@@ -105,17 +120,17 @@ function call(video, args1, args2, options, callback) {
     if (stderr) {
 
       // Try once to download video if no subtitles available
-      if (stderr.indexOf('WARNING: video doesn\'t have subtitles') !== -1 && !options.nocc) {
-        var cleanupOpt = opt[1];
+      if (!options.nocc && isNoSubsRegex.test(stderr)) {
+        var cleanupOpt = opt[1].reverse();
 
-        ['--write-sub', '--srt-lang=en', '--all-subs'].map(function map(item) {
-          var target = cleanupOpt.indexOf(item);
+        subs.map(function map(item) {
+          var target = reIndexOf(cleanupOpt, item);
           if (target > -1) { cleanupOpt.splice(target, 1); }
         });
 
         options.nocc = true;
 
-        return call(video, args1, cleanupOpt, options, callback);
+        return call(video, args1, cleanupOpt.reverse(), options, callback);
 
       }