much better formatting

trans.py

@@ -21,9 +21,11 @@ def cert_to_xml(cert_doc):
     }
     cert_doc['DCC']['administrativeData']['dccSoftware'].append(s)
     try: 
-        xml = render_template(dcc_template, doc=cert_doc['DCC'], utils=utils) 
-        xml = etree.canonicalize(prettify_xml(xml, indent=2, debug=False))
-        
+        xml = render_template(dcc_template, doc=cert_doc['DCC'], utils=utils)
+        xml = etree.canonicalize(xml, with_comments=True, strip_text=True)
+        # Bad side-effect: adds XML declaration again
+        xml = prettify_xml(xml, indent=2, debug=False)
+        xml = etree.canonicalize(xml, with_comments=True)
     except Exception as error:
         xml = '<error>' + str(error) + '</error>\n'