[gnome-sdk-images] Use mtime 1, not 0 in fontconfig caches

[Alexander Larsson <alexl src gnome org>]

commit 136d5cff7ea01caa096914b82392fe67f6d21ea1
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Aug 10 23:31:47 2016 +0200

    Use mtime 1, not 0 in fontconfig caches
    
    This is what ostree (and this flatpak) uses for checkouts now.

 org.gnome.Sdk.json.in |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 2a27993..d96e3e4 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -18,8 +18,8 @@
                  "/share/devhelp",
                  "/lib/systemd",
                  "*.la", "*.a"],
-    "cleanup-commands": [ "touch -d @0 /usr/share/fonts",
-                          "touch -d @0 /usr/share/fonts/*",
+    "cleanup-commands": [ "touch -d @1 /usr/share/fonts",
+                          "touch -d @1 /usr/share/fonts/*",
                           "fc-cache -fs"
                         ],
     "cleanup-platform": [ "/include",