[gnome-builder] plugins/editorui: fix scheme selector styling

[Christian Hergert <chergert src gnome org>]

commit 2cf711482122a676ac8fb8fe91f42698af42d727
Author: Christian Hergert <chergert redhat com>
Date:   Fri Aug 12 14:46:07 2022 -0700

    plugins/editorui: fix scheme selector styling

 src/plugins/editorui/gbp-editorui-scheme-selector.ui | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/editorui/gbp-editorui-scheme-selector.ui 
b/src/plugins/editorui/gbp-editorui-scheme-selector.ui
index 26011f795..8e1b21f68 100644
--- a/src/plugins/editorui/gbp-editorui-scheme-selector.ui
+++ b/src/plugins/editorui/gbp-editorui-scheme-selector.ui
@@ -5,11 +5,14 @@
       <object class="GtkFlowBox" id="flow_box">
         <signal name="child-activated" handler="style_scheme_activated_cb" swapped="true" 
object="GbpEditoruiSchemeSelector"/>
         <property name="hexpand">true</property>
-        <property name="column-spacing">8</property>
-        <property name="row-spacing">8</property>
+        <property name="column-spacing">12</property>
+        <property name="row-spacing">12</property>
         <property name="max-children-per-line">4</property>
         <property name="max-children-per-line">4</property>
         <property name="selection-mode">none</property>
+        <style>
+          <class name="style-schemes"/>
+        </style>
       </object>
     </child>
   </template>