containers.storage: improve ZFS compatibility

ZFS does not support OverlayFS by default, so the fuse-overlayfs mount
program should be configured to workaround.

srcpkgs/containers.storage/template

@@ -1,8 +1,9 @@
 # Template file for 'containers.storage'
 pkgname=containers.storage
 version=1.37.3
-revision=1
+revision=2
 hostmakedepends="go-md2man"
+depends="fuse-overlayfs"
 short_desc="Storage configuration shared by podman, buildah, and skopeo"
 maintainer="Cameron Nemo <cam@nohom.org>"
 license="Apache-2.0"
@@ -17,5 +18,6 @@ do_build() {
 
 do_install() {
 	vman "$_manpage"
+	vsed -e 's/^#mount_program = "/mount_program = "/' -i storage.conf
 	vinstall storage.conf 0644 usr/share/containers
 }