Updated the requirement on the xml2rfc version.

 - Legacy-Id: 14700

Author: levkowetz

requirements.txt

@@ -54,7 +54,7 @@ tqdm>=3.7.0
 Trac>=1.0.10,<1.2
 Unidecode>=0.4.18
 #wsgiref>=0.1.2
-xml2rfc>=2.5.0,!=2.6.0
+xml2rfc>=2.9.3,!=2.6.0
 xym==0.4.2,<1.0
 #zxcvbn-python>=4.4.14		# Not needed until we do back-end password entropy validation