Bugfix (segfault when starting a game after finishing all levels).

[evilplumber] / data / intro02.leg

You must use all pre-placed pipes.<br> For pieces with two pipes, <img src="IMGDIR/3_0.png" width="50" height="50"> and <img src="IMGDIR/4_0.png" width="50" height="50">,<br>both pipes must be used.