[gnome-boxes] Lower the detect-black limit again

[Alexander Larsson <alexl src gnome org>]

commit a9f40bdfa032aec3fb1ddef63272b7876f12827f
Author: Alexander Larsson <alexl redhat com>
Date:   Fri Aug 31 16:31:08 2012 +0200

    Lower the detect-black limit again
    
    The increased value for blackness detection had a lot
    of miss-triggering, like in the windows installer, while
    not detecting the default Windows screensaver anyway.
    
    So, better safe, we lower it to something that is far
    less likely to get false positives. The important thing
    is to not allow very dark screens that may be confused
    with a turned off box.

 src/machine.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/machine.vala b/src/machine.vala
index 68d5ca8..9671b54 100644
--- a/src/machine.vala
+++ b/src/machine.vala
@@ -294,7 +294,7 @@ private abstract class Boxes.Machine: Boxes.CollectionItem, Boxes.IPropertiesPro
                lock screen, nor a fullscreen white-on-black terminal with a single
                shell prompt, but do allow the terminal with a few lines of text.
             */
-            if (pixbuf_energy (small_screenshot) < 500)
+            if (pixbuf_energy (small_screenshot) < 50)
                 return;
 
             orig_pixbuf = small_screenshot;