list files again to avoid owning standard dirs in RPM

reverts commit 9d256d93a5

fixes file /usr/bin from install of openra-release.20130915-1.noarch
conflicts with file from package filesystem-3.2-13.fc19.x86_64

packaging/linux/rpm/buildpackage.sh

@@ -13,7 +13,7 @@ sed -i "s/{VERSION_FIELD}/$PKGVERSION/" openra.spec
 rootdir=`readlink -f $2`
 sed -i "s|{ROOT_DIR}|$rootdir|" openra.spec
 
-for x in `find $rootdir -type d`
+for x in `find $rootdir -type f`
 do
     y="${x#$rootdir}"
     sed -i "/%files/ a ${y}" openra.spec