[gnome-klotski] Fix button alignment.

[Arnaud B. <arnaudb src gnome org>]

commit 38ea1b0db6b95313511c257654bbacea72753a02
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Feb 10 18:39:55 2020 +0100

    Fix button alignment.

 data/klotski.ui | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/data/klotski.ui b/data/klotski.ui
index 0a7ce14..0631d83 100644
--- a/data/klotski.ui
+++ b/data/klotski.ui
@@ -324,6 +324,7 @@
         <child>
           <object class="GtkButton">
             <property name="visible">True</property>
+            <property name="valign">center</property>
             <property name="use-underline">True</property>
             <!-- Translators: in the headerbar, button that allows to directly restart the current puzzle 
(with a mnemonic that appears pressing Alt) -->
             <property name="label" translatable="yes">_Start Over</property>
@@ -340,6 +341,7 @@
         <child>
           <object class="GtkMenuButton">
             <property name="visible">True</property>
+            <property name="valign">center</property>
             <property name="use-underline">True</property>
             <!-- Translators: in the headerbar, button that allows via a popover to select a different 
puzzle (with a mnemonic that appears pressing Alt) -->
             <property name="label" translatable="yes">_Change Puzzle</property>
@@ -357,6 +359,7 @@
         <child>
           <object class="GtkMenuButton" id="menu_button">
             <property name="visible">True</property>
+            <property name="valign">center</property>
             <property name="can_focus">True</property>
             <property name="menu-model">app-menu</property>
             <child>