"v3.1.1" --> "v3.1.2"

templates/xml/dcc.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <dcc:digitalCalibrationCertificate
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="https://ptb.de/dcc https://www.ptb.de/dcc/v3.1.1/dcc.xsd"
+    xsi:schemaLocation="https://ptb.de/dcc https://www.ptb.de/dcc/v3.1.2/dcc.xsd"
     xmlns:dcc="https://ptb.de/dcc"
     xmlns:si="https://ptb.de/si"
-    schemaVersion="3.1.1">   
+    schemaVersion="3.1.2">   
   <!--
   DCC - Digital Calibration Certificate
   Copyright (C) 2021 - Physikalisch-Technische Bundesanstalt