AttributeError: 'NoneType' object has no attribute 'replace' on a specific feed

[pbrown280]

Feed URL: http://feeds.megaphone.fm/WWO2453800973

Throws this exception since upgrade to v3.13:

2021-05-11 15:47:10,754 [INFO] refreshing feed savage (http://feeds.megaphone.fm/WWO2453800973 -> [email protected])
2021-05-11 15:47:10,754 [INFO] fetch savage (http://feeds.megaphone.fm/WWO2453800973 -> [email protected])
2021-05-11 15:47:11,366 [INFO] process savage (http://feeds.megaphone.fm/WWO2453800973 -> [email protected])
Traceback (most recent call last):
File "/usr/local/bin/r2e", line 4, in
import('pkg_resources').run_script('rss2email==3.13', 'r2e')
File "/usr/lib/python3.9/site-packages/pkg_resources/init.py", line 651, in run_script
self.require(requires)[0].run_script(script_name, ns)
File "/usr/lib/python3.9/site-packages/pkg_resources/init.py", line 1455, in run_script
exec(script_code, namespace, namespace)
File "/usr/local/lib/python3.9/site-packages/rss2email-3.13-py3.9.egg/EGG-INFO/scripts/r2e", line 5, in
File "/usr/local/lib/python3.9/site-packages/rss2email-3.13-py3.9.egg/rss2email/main.py", line 199, in run
File "/usr/local/lib/python3.9/site-packages/rss2email-3.13-py3.9.egg/rss2email/command.py", line 91, in run
File "/usr/local/lib/python3.9/site-packages/rss2email-3.13-py3.9.egg/rss2email/feed.py", line 933, in run
File "/usr/local/lib/python3.9/site-packages/rss2email-3.13-py3.9.egg/rss2email/feed.py", line 394, in _process
File "/usr/local/lib/python3.9/site-packages/rss2email-3.13-py3.9.egg/rss2email/feed.py", line 544, in _process_entry
File "/usr/local/lib/python3.9/site-packages/rss2email-3.13-py3.9.egg/rss2email/feed.py", line 821, in _process_entry_content
File "/usr/lib64/python3.9/xml/sax/saxutils.py", line 27, in escape
data = data.replace("&", "&")
AttributeError: 'NoneType' object has no attribute 'replace'

[pbrown280]

Verified that this feed works on rss2email v3.11 on Fedora 31.

Throws this exception on rss2email v3.13 on Fedora 34.

(Needed to upgrade to v3.13 to get rss2email to work on Fedora 34.)