[gthumb] shortcuts: use Alt+Down to scroll to center

[Paolo Bacchilega <paobac src gnome org>]

commit 2e11b10a54bc337c801c19193ddd3d97065775c0
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Nov 22 10:27:07 2019 +0100

    shortcuts: use Alt+Down to scroll to center

 extensions/image_viewer/callbacks.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/extensions/image_viewer/callbacks.c b/extensions/image_viewer/callbacks.c
index ec08ad6d..3f60090d 100644
--- a/extensions/image_viewer/callbacks.c
+++ b/extensions/image_viewer/callbacks.c
@@ -55,7 +55,7 @@ static const GthShortcut shortcuts[] = {
        { "scroll-page-up", N_("Scroll up fast"), GTH_SHORTCUT_CONTEXT_VIEWER, 
GTH_SHORTCUT_CATEGORY_SCROLL_IMAGE, "<Shift>Up" },
        { "scroll-page-down", N_("Scroll down fast"), GTH_SHORTCUT_CONTEXT_VIEWER, 
GTH_SHORTCUT_CATEGORY_SCROLL_IMAGE, "<Shift>Down" },
 
-       { "scroll-to-center", N_("Scroll to center"), GTH_SHORTCUT_CONTEXT_VIEWER, 
GTH_SHORTCUT_CATEGORY_SCROLL_IMAGE, "<Primary>Down" },
+       { "scroll-to-center", N_("Scroll to center"), GTH_SHORTCUT_CONTEXT_VIEWER, 
GTH_SHORTCUT_CATEGORY_SCROLL_IMAGE, "<Alt>Down" },
 };