maemo/gconf: restore package from Alpine (!928)

main/gconf was removed upstream in Alpine:
  https://gitlab.alpinelinux.org/alpine/aports/commit/0878ac0f6e3d39cd0a748735c88f825fe9e1b8a5

However, some packages in maemo/ (e.g. libhildon) still depend on it.
This breaks the package parsing in bpo: https://builds.sr.ht/~postmarketos/job/146132
  ERROR: Package 'gconf-dev': Could not find aport, and could not find this package in any APKINDEX!

Add it to maemo/ for now to fix the error.

maemo/gconf/APKBUILD

+# Removed upstream in Alpine but libhildon still depends on it
+pkgname=gconf
+pkgver=3.2.6
+pkgrel=5
+pkgdesc="GNOME configuration system"
+url="http://projects.gnome.org/gconf"
+arch="all"
+license="GPL-2.0-or-later"
+depends_dev="libxml2-dev gtk+3.0-dev polkit-dev"
+makedepends="$depends_dev gobject-introspection-dev glib-dev intltool"
+subpackages="$pkgname-dev $pkgname-doc $pkgname-lang"
+source="https://download.gnome.org/sources/GConf/${pkgver%.*}/GConf-${pkgver}.tar.xz"
+
+builddir="$srcdir"/GConf-"$pkgver"
+
+build() {
+	cd "$builddir"
+	./configure \
+		--build=$CBUILD \
+		--host=$CHOST \
+		--prefix=/usr \
+		--sysconfdir=/etc \
+		--disable-static \
+		--disable-orbit \
+		--enable-gsettings-backend
+	make
+}
+
+check() {
+	cd "$builddir"
+	make check
+}
+
+package() {
+	cd "$builddir"
+	make DESTDIR="$pkgdir" install
+}
+
+sha512sums="35f5f659f9d03f7531a7102adacbda0eb310d8a55a831c768c91a82e07dae21247726e00e0e411f63b1de9ade0f042ded572a3ea4a4b2ad3135231f344540b58  GConf-3.2.6.tar.xz"