metsHdr used instead of fileSec in dfg-viewer.xsl

[pontus-osterdahl]

Describe the bug
In the very useful new dfg-viewer.xsl there appears to be a small typo.
I believe in:

kitodo-production/Kitodo/src/main/resources/xslt/dfg-viewer.xsl

Lines 39 to 45 in 71e2e14

	<!-- mets:fileSec -->
	<xsl:template match="mets:fileSec">
	<mets:metsHdr>
	<xsl:copy-of select="@*"/>
	<xsl:copy-of select="node()"/>
	</mets:metsHdr>
	</xsl:template>

We should have:

<!-- mets:fileSec -->  
<xsl:template match="mets:fileSec">
  <mets:fileSec>   
    <xsl:copy-of select="@*"/>   
    <xsl:copy-of select="node()"/>  
  </mets:fileSec>  
</xsl:template>