Fix a small bug caused by the refactoring commit 28c15f9

Clicking of the title of the "All tracks", "Playlist", or "Internet
radio" views always started to play the first list item, even if the
Shuffle mode was active. In this case, it was supposed to start playing
from a random item.

js/app/controllers/views/alltracksviewcontroller.js

@@ -35,7 +35,7 @@ angular.module('Music').controller('AllTracksViewController', [
 			_.each(_unsubFuncs, function(func) { func(); });
 		});
 
-		function play(startIndex = 0) {
+		function play(startIndex = null) {
 			playlistService.setPlaylist('alltracks', _tracks, startIndex);
 			playlistService.publish('play');
 		}

js/app/controllers/views/playlistviewcontroller.js

@@ -58,7 +58,7 @@ angular.module('Music').controller('PlaylistViewController', [
 			});
 		};
 
-		function play(startIndex = 0) {
+		function play(startIndex = null) {
 			let id = 'playlist-' + $scope.playlist.id;
 			playlistService.setPlaylist(id, $scope.tracks, startIndex);
 			playlistService.publish('play');

js/app/controllers/views/radioviewcontroller.js

@@ -75,7 +75,7 @@ angular.module('Music').controller('RadioViewController', [
 			);
 		}
 
-		function play(startIndex = 0) {
+		function play(startIndex = null) {
 			playlistService.setPlaylist('radio', $scope.stations, startIndex);
 			playlistService.publish('play');
 		}