Simplify use of an initial volume figure.

player.c

@@ -2096,8 +2096,6 @@ void *player_thread_func(void *arg) {
   pthread_setcancelstate(oldState, NULL);
 
   double initial_volume = config.airplay_volume; // default
-  if (conn->initial_airplay_volume_set)          // if we have been given an initial volume
-    initial_volume = conn->initial_airplay_volume;
   // set the default volume to whatever it was before, as stored in the config airplay_volume
   debug(2, "Set initial volume to %f.", initial_volume);
   player_volume(initial_volume, conn); // will contain a cancellation point if asked to wait