Fix mistaken 'u' inserted into xml

Change-Id: I1bdc2ec3cf9c94b0d48be99a4409b39dc6d77389
Reviewed-on: https://gerrit.libreoffice.org/14961Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sd/uiconfig/sdraw/toolbar/linesbar.xml

-u<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE toolbar:toolbar PUBLIC "-//OpenOffice.org//DTD OfficeDocument 1.0//EN" "toolbar.dtd">
 <!--
  * This file is part of the LibreOffice project.
@@ -28,3 +28,4 @@ u<?xml version="1.0" encoding="UTF-8"?>
  <toolbar:toolbaritem xlink:href=".uno:Polygon_Diagonal_Unfilled" toolbar:style="radio"/>
  <toolbar:toolbaritem xlink:href=".uno:Freeline_Unfilled" toolbar:style="radio"/>
 </toolbar:toolbar>
+