pdftk: unbreak build (not -jX safe).

srcpkgs/pdftk/template

@@ -4,7 +4,6 @@ version=2.02
 revision=1
 wrksrc="${pkgname}-${version}-dist"
 build_wrksrc=${pkgname}
-build_style=gnu-makefile
 hostmakedepends="unzip gcc-gcj"
 makedepends="libgcj-devel"
 nocross=yes
@@ -15,8 +14,9 @@ homepage="https://www.pdflabs.com/tools/pdftk-server/"
 distfiles="http://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/${pkgname}-${version}-src.zip"
 checksum=118f6a25fd3acaafb58824dce6f97cdc07e56050e666b90e4c4ef426ea37b8c1
 
-pre_configure() {
+do_build() {
 	cp ${FILESDIR}/Makefile Makefile
+	make
 }
 do_install() {
 	vbin pdftk