[gtk+] docs: Ignore gtksnapshotprivate.h

[Matthias Clasen <matthiasc src gnome org>]

commit 5c1af1af04f4e5f3e64d81aab8814867aeef2680
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Nov 18 08:10:01 2016 -0500

    docs: Ignore gtksnapshotprivate.h

 docs/reference/gtk/Makefile.am |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/gtk/Makefile.am b/docs/reference/gtk/Makefile.am
index 9bc86ae..b99f6b4 100644
--- a/docs/reference/gtk/Makefile.am
+++ b/docs/reference/gtk/Makefile.am
@@ -157,6 +157,7 @@ IGNORE_HFILES = \
        gtksidebarrowprivate.h          \
        gtksizegroup-private.h          \
        gtksizerequestcacheprivate.h    \
+       gtksnapshotprivate.h            \
        gtkstyleanimationprivate.h      \
        gtkstylecascadeprivate.h        \
        gtkstylecontextprivate.h        \