harvestInfo.performer in warcinfo records is not included in harvestInfo.xml

In 5.1, the harvestInfo.performer included in warcinfo records is empty. And is not included in harvestInfo.xml.

#added by NetarchiveSuite Version: 5.1 (<a href="https://github.com/netarchivesuite/netarchivesuite/commit/cde61d78299cabccae6195908b81ef77c84a76b9">cde61d7829</a>)
harvestInfo.version: 0.5
harvestInfo.jobId: 20
harvestInfo.channel: CIBLEE
harvestInfo.harvestNum: 3
harvestInfo.origHarvestDefinitionID: 2
harvestInfo.maxBytesPerDomain: -1
harvestInfo.maxObjectsPerDomain: 50
harvestInfo.orderXMLName: default_NAS5_1_KLM
harvestInfo.origHarvestDefinitionName: test saa
harvestInfo.scheduleName: annuelle
harvestInfo.harvestFilenamePrefix: BnF-20-2
harvestInfo.jobSubmitDate: Mon Jul 25 13:08:46 CEST 2016
harvestInfo.performer:
harvestInfo.audience: champ public

<?xml version="1.0" encoding="UTF-8"?>
<harvestInfo>
<version>0.5</version>
<jobId>20</jobId>
<channel>CIBLEE</channel>
<harvestNum>3</harvestNum>
<origHarvestDefinitionID>2</origHarvestDefinitionID>
<maxBytesPerDomain>-1</maxBytesPerDomain>
<maxObjectsPerDomain>50</maxObjectsPerDomain>
<orderXMLName>default_NAS5_1_KLM</orderXMLName>
<origHarvestDefinitionName>test saa</origHarvestDefinitionName>
<origHarvestDefinitionComments>Collecte réalisée avec NAS 5.1 pour contrôler les WARC de données et de métadonnées.</origHarvestDefinitionComments>
<scheduleName>annuelle</scheduleName>
<harvestFilenamePrefix>BnF-20-2</harvestFilenamePrefix>
<jobSubmitDate>2016-07-25T11:08:46Z</jobSubmitDate>
<audience>champ public</audience>
</harvestInfo>