[gimp] app: fix the last commit: it's n_components not 4, sigh

[Michael Natterer <mitch src gnome org>]

commit d49e33da4ac4c1bb6a7d6f93340aa05363f2b477
Author: Michael Natterer <mitch gimp org>
Date:   Mon Apr 8 03:33:39 2013 +0200

    app: fix the last commit: it's n_components not 4, sigh

 app/core/gimpimage-contiguous-region.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/app/core/gimpimage-contiguous-region.c b/app/core/gimpimage-contiguous-region.c
index 554a2b8..9b94dff 100644
--- a/app/core/gimpimage-contiguous-region.c
+++ b/app/core/gimpimage-contiguous-region.c
@@ -239,7 +239,7 @@ gimp_image_contiguous_region_by_color (GimpImage            *image,
                                     select_transparent,
                                     select_criterion);
 
-          src  += 4;
+          src  += n_components;
           dest += 1;
         }
     }