[Change] Reset interference on player load/creation.

src/player.c

@@ -656,6 +656,11 @@ void player_cleanup(void) {
     pilot_free(player);
     player = NULL;
   }
+
+  /* Clean up interference. */
+  interference_alpha = 0.;
+  interference_layer = 0;
+  interference_t     = 0.;
 }
 
 static int player_soundReserved = 0; /**< Has the player already reserved sound? */