[aur-dev] Accept packages with build and/or package function (FS#19914)

With makepkg 3.4.0 is possible to avoid the build() function and use package() only. Current AUR checks only for build() when it parsing PKGBUILD, this patch checks for both. build() OR package() function is needed. -- Andrea Scarpino - andreascarpino.it KDE Maintainer in Arch Linux