[gnome-text-editor] propertiesdialog: add mnemonic for update button

[Christian Hergert <chergert src gnome org>]

commit 738b994a0e6ceff07e116fd993268175262aa172
Author: Christian Hergert <chergert redhat com>
Date:   Wed Jan 5 15:59:53 2022 -0800

    propertiesdialog: add mnemonic for update button

 src/editor-properties-dialog.ui | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/editor-properties-dialog.ui b/src/editor-properties-dialog.ui
index e0dd79c..a7c8cd7 100644
--- a/src/editor-properties-dialog.ui
+++ b/src/editor-properties-dialog.ui
@@ -11,7 +11,8 @@
       <object class="GtkHeaderBar">
         <child type="start">
           <object class="GtkButton" id="rescan">
-            <property name="label" translatable="yes">Update</property>
+            <property name="label" translatable="yes">_Update</property>
+            <property name="use-underline">true</property>
             <property name="visible">false</property>
             <property name="action-name">win.rescan</property>
           </object>