Swan boat sprites yellow color improperly remapped

[ZeeMaji]

The swan boats use yellow in their sprites which was fine in RCT1, however in RCT2 it seems like chris forgot to update it to account for yellow now being used as the third remap color which results in the swan boats having black splotches on their beaks similar to the error which affected many WWTT objects.

This might affect more RCT2 base game objects so i may add more to this issue should i find any extras. afterwards i'll make a fix for all of them.