Enforce utf-8 encoding for account chart generated by xsltproc

Closes #14617

modules/account/account_chart.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="utf-8"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <tryton>

modules/account/account_chart_de.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="utf-8"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <tryton>

modules/account/account_chart_en.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="utf-8"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <tryton>

modules/account/account_chart_es.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="utf-8"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <tryton>

modules/account/account_chart_fr.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="utf-8"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <tryton>

modules/account/localize.xsl

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <xsl:transform version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
     <xsl:strip-space elements="*"/>
-    <xsl:output method="xml" indent="yes"/>
+    <xsl:output method="xml" encoding="utf-8" indent="yes"/>
     <xsl:param name="lang"/>
     <xsl:template match="data">
         <xsl:copy>