[glib] build: Pass ZLIB_CFLAGS for gio build

[Colin Walters <walters src gnome org>]

commit a187199efd7eb16f500cef31c950d4eafbfe3a4b
Author: kotarou <nospam kotarou dono gmail com>
Date:   Wed Aug 3 08:46:04 2011 -0400

    build: Pass ZLIB_CFLAGS for gio build
    
    Otherwise we will fail if zlib is in an alternative prefix.
    
    Commit message written by Colin Walters <walters verbum org>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=655769

 gio/Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gio/Makefile.am b/gio/Makefile.am
index 148f4c5..295c60d 100644
--- a/gio/Makefile.am
+++ b/gio/Makefile.am
@@ -415,6 +415,8 @@ libgio_2_0_la_LIBADD = \
 	$(XATTR_LIBS) 					\
 	$(NULL)
 
+libgio_2_0_la_CPPFLAGS = $(ZLIB_CFLAGS) $(AM_CPPFLAGS)
+
 if PLATFORM_WIN32
 no_undefined = -no-undefined
 endif