gnome-flashback: fix cross build

srcpkgs/gnome-flashback/template

@@ -2,9 +2,10 @@
 pkgname=gnome-flashback
 version=3.34.1
 revision=1
+build_helper=gir
 build_style=gnu-configure
 configure_args="--enable-compile-warnings=minimum"
-hostmakedepends="pkg-config automake glib-devel"
+hostmakedepends="pkg-config automake glib-devel gettext"
 makedepends="gtk+3-devel gsettings-desktop-schemas-devel
  libglib-devel gdk-pixbuf-devel upower-devel ibus-devel polkit-devel
  pulseaudio-devel libcanberra-devel libxcb-devel libX11-devel pango-devel
@@ -17,4 +18,3 @@ license="GPL-3.0-or-later"
 homepage="https://wiki.gnome.org/Projects/GnomeFlashback"
 distfiles="${GNOME_SITE}/${pkgname}/${version%.*}/${pkgname}-${version}.tar.xz"
 checksum=ddba0c9661ad93b58ccbde267f6ecbc02da2c15f9d38d87d5504f4670c2fbc77
-nocross="gobject-introspection"