[gimp-perl] Make examples/xachshadows work with alpha-less layer. Bug 728567

[Ed J <edj src gnome org>]

commit 3034bba49c8134dec06f762ffd21d339af078b60
Author: Ed J <m8r-35s8eo mailinator com>
Date:   Sat Apr 19 19:05:33 2014 +0100

    Make examples/xachshadows work with alpha-less layer. Bug 728567

 examples/xachshadow |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/examples/xachshadow b/examples/xachshadow
index 0f88468..5841f48 100755
--- a/examples/xachshadow
+++ b/examples/xachshadow
@@ -44,7 +44,7 @@ register "xach_shadows",
         Gimp::Context->push();
  #     $selection_flag = 0;
        if (!$drawable->has_alpha) {
-               $drawable->add_alpha;
+               $drawable->Gimp::Layer::add_alpha; # not drawable method
                };
         Gimp::Context->set_foreground('white');
         Gimp::Context->set_background('black');