cppcx: Update addSlave prototype

cppcx/MediaPlayerCX.cpp

@@ -403,9 +403,9 @@ namespace libVLCX
         return m_mp.setSpu(i_spu);
     }
 
-    bool MediaPlayer::addSlave(SlaveType type, Platform::String^ uri)
+    bool MediaPlayer::addSlave(SlaveType type, Platform::String^ uri, bool select)
     {
-        return m_mp.addSlave(static_cast<VLC::MediaSlave::Type>(type), VLCString(uri));
+        return m_mp.addSlave(static_cast<VLC::MediaSlave::Type>(type), VLCString(uri), select);
     }
 
     int64_t MediaPlayer::spuDelay()

cppcx/MediaPlayerCX.hpp

@@ -855,7 +855,7 @@ namespace libVLCX
         */
         int setSpu(int i_spu);
 
-        bool addSlave(SlaveType type, Platform::String^ uri);
+        bool addSlave(SlaveType type, Platform::String^ uri, bool select);
 
         /**
         * Get the current subtitle delay. Positive values means subtitles are