Fix the issue tracker link of the item sets builder.
Fix the issue tracker link of the item sets builder.

league-of-legends-devs/lol-item-sets-generator.org,Ilshidur/lol-item-sets-generator.org,Ilshidur/lol-item-sets-generator.org,Ilshidur/lol-item-sets-generator.org,league-of-legends-devs/lol-item-sets-generator.org,league-of-legends-devs/lol-item-sets-generator.org