[gnome-builder] improve preferences column vertical spacing

[Christian Hergert <chergert src gnome org>]

commit a996bb68912fcf44a134f8bad5f437b6cb8505af
Author: Allan Day <allanpday gmail com>
Date:   Mon Jul 18 15:16:02 2016 +0100

    improve preferences column vertical spacing
    
    Headings were too far away from their respective lists, making
    the layout harder to read and look untidy.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=768926

 contrib/egg/egg-column-layout.c             |    2 +-
 libide/preferences/ide-preferences-group.ui |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/contrib/egg/egg-column-layout.c b/contrib/egg/egg-column-layout.c
index a1fef66..dc2d01c 100644
--- a/contrib/egg/egg-column-layout.c
+++ b/contrib/egg/egg-column-layout.c
@@ -36,7 +36,7 @@ typedef struct
 
 #define COLUMN_WIDTH_DEFAULT   500
 #define COLUMN_SPACING_DEFAULT 24
-#define ROW_SPACING_DEFAULT    12
+#define ROW_SPACING_DEFAULT    24
 
 G_DEFINE_TYPE_WITH_PRIVATE (EggColumnLayout, egg_column_layout, GTK_TYPE_CONTAINER)
 
diff --git a/libide/preferences/ide-preferences-group.ui b/libide/preferences/ide-preferences-group.ui
index 3a0e533..a467535 100644
--- a/libide/preferences/ide-preferences-group.ui
+++ b/libide/preferences/ide-preferences-group.ui
@@ -7,7 +7,7 @@
     <child>
       <object class="GtkBox">
         <property name="orientation">vertical</property>
-        <property name="spacing">12</property>
+        <property name="spacing">8</property>
         <property name="visible">true</property>
         <child>
           <object class="GtkLabel" id="title">