Resolves: tdf#118115 add missing help response id

Change-Id: Ie050285cc10d82cf80e560be3f1766c50dd1527c
Reviewed-on: https://gerrit.libreoffice.org/57715
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

cui/uiconfig/ui/signatureline.ui

@@ -321,6 +321,7 @@
     <action-widgets>
       <action-widget response="-6">cancel</action-widget>
       <action-widget response="-5">ok</action-widget>
+      <action-widget response="-11">help</action-widget>
     </action-widgets>
   </object>
 </interface>