OAI plugin: Change order of tags for "Identify"

Several web based OAI PMH tools fail when parsing Goobi's OAI data:

http://oval.base-search.net/ (BASE OAI-PMH Validator)
http://validator.oaipmh.com/ (OAI PMH Validator & data extractor Tool)
http://re.cs.uct.ac.za/ (Open Archives Initiative - Repository Explorer)

All three complain about an unexpected tag "earliestDatestamp" which
obviously comes too early for those tools.

The OAI PMH reference documentation uses a different ordering with
"adminEmail" coming before "earliestDatestamp", so change Goobi
accordingly and make the tools happy.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

dlf/plugins/oai/class.tx_dlf_oai.php

@@ -975,14 +975,14 @@ class tx_dlf_oai extends tx_dlf_plugin {
 								   'baseURL', $baseURL));
 		$Identify->appendChild($this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/',
 								   'protocolVersion', '2.0'));
+		$Identify->appendChild($this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/',
+								   'adminEmail', $adminEmail));
 		$Identify->appendChild($this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/',
 								   'earliestDatestamp', $earliestDatestamp));
 		$Identify->appendChild($this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/',
 								   'deletedRecord', 'transient'));
 		$Identify->appendChild($this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/',
 								   'granularity', 'YYYY-MM-DDThh:mm:ssZ'));
-		$Identify->appendChild($this->oai->createElementNS('http://www.openarchives.org/OAI/2.0/',
-								   'adminEmail', $adminEmail));
 
 		return $Identify;
 	}