[gdk-pixbuf] png: make sure we still build with libpng 1.2

[Cosimo Cecchi <cosimoc src gnome org>]

commit a4dd465371ece0179cd6d85ef16ed61aae145db4
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Tue Sep 4 12:30:05 2012 -0400

    png: make sure we still build with libpng 1.2
    
    png_const_bytep doesn't exist there.

 gdk-pixbuf/io-png.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gdk-pixbuf/io-png.c b/gdk-pixbuf/io-png.c
index 105723e..fd8ac56 100644
--- a/gdk-pixbuf/io-png.c
+++ b/gdk-pixbuf/io-png.c
@@ -1013,7 +1013,7 @@ static gboolean real_save_png (GdkPixbuf        *pixbuf,
         if (icc_profile != NULL) {
                 png_set_iCCP (png_ptr, info_ptr,
                               "ICC profile", PNG_COMPRESSION_TYPE_BASE,
-                              (png_const_bytep) icc_profile, icc_profile_size);
+                              (png_bytep) icc_profile, icc_profile_size);
         }
 #endif