Resolves fdo#80477: duplicate key for Help button in Start Center

Change-Id: If46baf8613c6202e84a985ad7e2ce658e1d42193
Reviewed-on: https://gerrit.libreoffice.org/10102Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sfx2/uiconfig/ui/startcenter.ui

@@ -260,14 +260,13 @@
                         <property name="orientation">vertical</property>
                         <child>
                           <object class="GtkButton" id="help">
-                            <property name="label">gtk-help</property>
+                            <property name="label">He_lp</property>
                             <property name="visible">True</property>
                             <property name="can_focus">True</property>
                             <property name="receives_default">True</property>
                             <property name="has_tooltip">True</property>
                             <property name="relief">none</property>
                             <property name="use_underline">True</property>
-                            <property name="use_stock">True</property>
                           </object>
                           <packing>
                             <property name="expand">False</property>