[aur-general] Delete duplicate xampp package

Currently, there are two packages for xampp that do the same thing: xampp-linux, which was there two years earlier and just xampp. The xampp PKGBUILD is pretty much the xampp-linux PKGBUILD with added stuff for taking care of x86_64 because the regular xampp-linux package will not work properly with x86_64. Therefore, this situation is a little complicated. I propose the deletion of the xampp package and notification of the xampp-linux package maintainer in order to make the package x86_64 compatible.