[gtk+] docs: Ignore GtkTooltipWindow's private header file

[Emmanuele Bassi <ebassi src gnome org>]

commit d694a9a83b3e683acd99789a3d48b40b7841fda2
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Nov 10 13:24:05 2015 +0000

    docs: Ignore GtkTooltipWindow's private header file

 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 ce6d6e2..fa0dcb9 100644
--- a/docs/reference/gtk/Makefile.am
+++ b/docs/reference/gtk/Makefile.am
@@ -172,6 +172,7 @@ IGNORE_HFILES = \
        gtktoolbarprivate.h             \
        gtktoolpaletteprivate.h         \
        gtktooltipprivate.h             \
+       gtktooltipwindowprivate.h       \
        gtktreeprivate.h                \
        gtkwidgetprivate.h              \
        gtkwin32themeprivate.h          \