Fix typing into score entry

data/interface.ui

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
   SPDX-FileCopyrightText: 2012-2021 Bruce Cowan <bruce@bcowan.me.uk>
+
   SPDX-License-Identifier: GPL-3.0-or-later
 -->
 <interface>
@@ -8,7 +9,6 @@
   <object class="GtkAdjustment" id="adjustment1">
     <property name="upper">200</property>
     <property name="step_increment">1</property>
-    <property name="page_increment">10</property>
   </object>
   <menu id="menu">
     <section>
@@ -25,17 +25,14 @@
     </section>
   </menu>
   <template class="RugbyAppWindow" parent="GtkApplicationWindow">
-    <property name="can_focus">0</property>
     <property name="title" translatable="yes">Rugby</property>
     <child>
       <object class="GtkScrolledWindow">
         <property name="height_request">600</property>
         <child>
           <object class="GtkViewport">
-            <property name="can_focus">0</property>
             <child>
               <object class="GtkListBox" id="listbox">
-                <property name="can_focus">0</property>
                 <property name="selection_mode">none</property>
                 <style>
                   <class name="rich-list"/>
@@ -56,17 +53,15 @@
     </child>
     <child type="titlebar">
       <object class="GtkHeaderBar">
-        <property name="can_focus">0</property>
         <child>
           <object class="GtkLabel">
-            <property name="can_focus">0</property>
             <property name="label" translatable="yes">Score:</property>
           </object>
         </child>
         <child>
           <object class="GtkSpinButton" id="scorespin">
-            <property name="text" translatable="yes">0</property>
             <property name="adjustment">adjustment1</property>
+            <property name="focusable">1</property>
           </object>
         </child>
         <child type="end">