Merge branch '6538-auto-check-dkim-active' into 'develop'

Enable DKIM when generating a Private-key #6538

See merge request ispconfig/ispconfig3!1766

Author: Till Brehm

interface/web/mail/templates/mail_domain_edit.htm

@@ -169,6 +169,7 @@
 			$("#dkim_public").val(data.dkim_public);
 			$("#dkim_private").val(data.dkim_private);
 			$("#dns_record").val(dns);
+			$('#dkim').prop("checked", true);
 		});
 	};
 </script>