xmlto: make libpaper optional

it's not needed for the common case of html/man output, so
make it optional

Author: lazka

mingw-w64-xmlto/PKGBUILD

@@ -4,23 +4,26 @@ _realname=xmlto
 pkgbase=mingw-w64-${_realname}
 pkgname=("${MINGW_PACKAGE_PREFIX}-${_realname}")
 pkgver=0.0.29
-pkgrel=1
+pkgrel=2
 pkgdesc="Convert xml to many other formats (mingw-w64)"
 arch=('any')
 mingw_arch=('mingw64' 'ucrt64' 'clang64' 'clangarm64')
 url='https://pagure.io/xmlto/'
 license=('spdx:GPL-2.0-or-later')
 depends=(
   "${MINGW_PACKAGE_PREFIX}-libxslt"
-  "${MINGW_PACKAGE_PREFIX}-libpaper"
   "${MINGW_PACKAGE_PREFIX}-libxml2"
 )
 makedepends=(
   "${MINGW_PACKAGE_PREFIX}-autotools"
   "${MINGW_PACKAGE_PREFIX}-cc"
   "${MINGW_PACKAGE_PREFIX}-docbook-xsl"
+  "${MINGW_PACKAGE_PREFIX}-libpaper"
   "flex"
 )
+optdepends=(
+  "${MINGW_PACKAGE_PREFIX}-libpaper: paper size detection for PDF/PS/FO output"
+)
 _commit="6fa6a0e07644f20abf2596f78a60112713e11cbe"
 source=("https://pagure.io/xmlto/archive/${pkgver}/${_realname}-${pkgver}.tar.gz"
         0002-xmlto-use-windows-paths-in-xml.patch