[gdk-pixbuf] Quell another automake warning

[Matthias Clasen <matthiasc src gnome org>]

commit fb71dc51cbdf7d7a572f9ba5dfbf0496f75c2bbf
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Dec 19 15:45:30 2013 -0500

    Quell another automake warning

 tests/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index efa3c7c..5b1de29 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,6 +1,6 @@
 include $(top_srcdir)/glib-tap.mk
 
-INCLUDES =                             \
+AM_CPPFLAGS =                          \
        -I$(top_srcdir)                 \
        -I$(top_srcdir)/gdk-pixbuf      \
        $(GDK_PIXBUF_DEBUG_FLAGS)       \