Fix fa170b9: [SDL2] forgot to use GetGameInterval where needed

src/video/sdl2_v.cpp

@@ -778,11 +778,11 @@ void VideoDriver_SDL::LoopOnce()
 
 	if (cur_ticks >= next_game_tick || (_fast_forward && !_pause_mode)) {
 		if (_fast_forward && !_pause_mode) {
-			next_game_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+			next_game_tick = cur_ticks + this->GetGameInterval();
 		} else {
-			next_game_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+			next_game_tick += this->GetGameInterval();
 			/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
-			if (next_game_tick < cur_ticks - std::chrono::milliseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_game_tick = cur_ticks;
+			if (next_game_tick < cur_ticks - ALLOWED_DRIFT * this->GetGameInterval()) next_game_tick = cur_ticks;
 		}
 
 		/* The gameloop is the part that can run asynchronously. The rest