Revert "main/libtool: disable -dlpreopen nonsense"

This reverts commit 0ab24492.
which broke imagemagick.

fixes #7915

main/libtool/APKBUILD

 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=libtool
 pkgver=2.4.6
-pkgrel=3
+pkgrel=4
 pkgdesc="A generic library support script"
 arch="all"
 license='GPL'
@@ -24,7 +24,6 @@ build() {
 		--prefix=/usr \
 		--disable-static \
 		|| return 1
-	echo '#undef HAVE_LIBDLLOADER' >> config.h
 	make
 }