[perl-Cairo] Fix compilation against a cairo without PS surface support

[Torsten Schönfeld <tsch src gnome org>]

commit 04470b0be19c15030794988f983878673b283755
Author: Torsten Schönfeld <kaffeetisch gmx de>
Date:   Sat Apr 30 19:11:24 2011 +0200

    Fix compilation against a cairo without PS surface support

 Makefile.PL |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/Makefile.PL b/Makefile.PL
index 4c31262..490edd9 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -328,6 +328,7 @@ if ($have_cairo_1_8) {
 my %object_guards = ();
 
 my %enum_guards = (
+	cairo_ps_level_t    => '#ifdef CAIRO_HAS_PS_SURFACE',
 	cairo_svg_version_t => '#ifdef CAIRO_HAS_SVG_SURFACE',
 );