Correcting live first segment

Start time was going back one segment too far due to an array indexing
error

@@ -143,10 +143,10 @@ videojs.Hls.prototype.handleSourceOpen = function() {
 
 
     // start live playlists 30 seconds before the current time
     // start live playlists 30 seconds before the current time
     if (this.duration() === Infinity && this.mediaIndex === 0 && selectedPlaylist.segments) {
     if (this.duration() === Infinity && this.mediaIndex === 0 && selectedPlaylist.segments) {
-      tailIterator = selectedPlaylist.segments.length - 1;
+      tailIterator = selectedPlaylist.segments.length;
       tailDuration = 0;
       tailDuration = 0;
       while (tailDuration < 30 && tailIterator > 0) {
       while (tailDuration < 30 && tailIterator > 0) {
-        tailDuration += selectedPlaylist.segments[tailIterator].duration;
+        tailDuration += selectedPlaylist.segments[tailIterator - 1].duration;
         tailIterator--;
         tailIterator--;
       }
       }
       this.mediaIndex = tailIterator;
       this.mediaIndex = tailIterator;

@@ -1065,7 +1065,7 @@ test('live playlist starts 30s before live', function() {
 
 
   player.hls.playlists.trigger('loadedmetadata');
   player.hls.playlists.trigger('loadedmetadata');
 
 
-  strictEqual(player.hls.mediaIndex, 5, 'mediaIndex is updated after the reload');
+  strictEqual(player.hls.mediaIndex, 6, 'mediaIndex is updated after the reload');
 });
 });
 
 
 test('mediaIndex is zero before the first segment loads', function() {
 test('mediaIndex is zero before the first segment loads', function() {