Corrects release date

extension.xml

@@ -6,7 +6,7 @@
 	<label><![CDATA[TeemIp Zone Management]]></label>
 	<description><![CDATA[TeemIp extension to manage DNS views, zones and DNS records]]></description>
 	<version>2.7.1</version>
-	<release_date>2020-04-01</release_date>
+	<release_date>2021-04-01</release_date>
 	<version_description><![CDATA[Enhancements from 2.7.0: See Wiki at https://wiki.teemip.net/doku.php?id=extensions:teemip-zone-mgmt]]></version_description>
 	<itop_version_min>2.7.0</itop_version_min>
 	<status>stable</status>