2.1.14 GUI crash: ALLOW_SENDER_OVERRIDES AttributeError

I just upgraded to 2.1.14 from 2.1.12. When trying to login to the admin interface for a list, Mailman crashes and I get a "bug" message in the browser. The Mailman error log contains this:

...
admin(24739): PYTHONPATH: /opt/mailman
admin(24739): SCRIPT_FILENAME: /opt/mailman/cgi-bin/admin
admin(24739): SERVER_ADMIN: [edited out]
admin(24739): HTTP_HOST: [edited out]
admin(24739): HTTPS: on
admin(24739): HTTP_CONNECTION: keep-alive
admin(24739): HTTP_CACHE_CONTROL: max-age=0
admin(24739): REQUEST_URI: /mailman/admin/[edited out]
admin(24739): HTTP_ACCEPT: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
admin(24739): GATEWAY_INTERFACE: CGI/1.1
admin(24739): REMOTE_PORT: 36978
admin(24739): HTTP_ACCEPT_LANGUAGE: en-us
admin(24739): CONTENT_TYPE: application/x-www-form-urlencoded
admin(24739): HTTP_ACCEPT_ENCODING: gzip, deflate
admin(24739): UNIQUE_ID: TJuulolSrxMAAGCeOtwAAAAA
Sep 23 12:47:11 2010 admin(24744): @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
admin(24744): [----- Mailman Version: 2.1.14 -----]
admin(24744): [----- Traceback ------]
admin(24744): Traceback (most recent call last):
admin(24744): File "/opt/mailman/scripts/driver", line 112, in run_main
admin(24744): main()
admin(24744): File "/opt/mailman/Mailman/Cgi/admin.py", line 175, in main
admin(24744): change_options(mlist, category, subcat, cgidata, doc)
admin(24744): File "/opt/mailman/Mailman/Cgi/admin.py", line 1299, in change_options
admin(24744): gui.handleForm(mlist, category, subcat, cgidata, doc)
admin(24744): File "/opt/mailman/Mailman/Gui/GUIBase.py", line 144, in handleForm
admin(24744): for item in self.GetConfigInfo(mlist, category, subcat):
admin(24744): File "/opt/mailman/Mailman/Gui/General.py", line 418, in GetConfigInfo
admin(24744): if mm_cfg.ALLOW_SENDER_OVERRIDES:
admin(24744): AttributeError: 'module' object has no attribute 'ALLOW_SENDER_OVERRIDES'
admin(24744): [----- Python Information -----]
admin(24744): sys.version = 2.4.4 (#1, Jan 9 2007, 23:31:33) [C]
admin(24744): sys.executable = /usr/bin/python
admin(24744): sys.prefix = /usr
admin(24744): sys.exec_prefix = /usr
admin(24744): sys.path = ['/opt/mailman/pythonlib', '/opt/mailman', '/opt/mailman/scripts', '/opt/mailman', '/usr/lib/python24.zip', '/usr/lib/python2.4/', '/usr/lib/python2.4/plat-sunos5', '/usr/lib/python2.4/lib-tk', '/usr/lib/python2.4/lib-dynload', '/usr/lib/python2.4/site-packages']
admin(24744): sys.platform = sunos5

...

By editing the /Mailman/Gui/General.py file (line 418) and removing the offending section, I'm able to login to and use the admin area. However, it's clearly also removing some functionality:

# Suppression of Sender header modification
#if mm_cfg.ALLOW_SENDER_OVERRIDES:
# rtn.append(
# ('include_sender_header', mm_cfg.Radio,
# (_('No'), _('Yes')), 0,
# _("""Should the <tt>Sender</tt> header be rewritten for this
# mailing list to avoid stray bounces? <em>Yes</em> is
# recommended."""),

# _("""<a href="http://www.faqs.org/rfcs/rfc2822.html">RFC
# 2822</a> defines the <tt>Sender</tt> header and defines it
# as "the mailbox of the agent responsible for the actual
# transmission of the message." Mailman replaces this header
# by default with the list's bounce address.

# <p>While it is debatable if Mailman is such an agent, setting
# this header helps directing bounces from some broken MTAs to
# the right destination. On the other hand, some mail
# readers show unexpected behaviour if this header is set (like
# missing addresses in forwarded mails and copies sent to the
# bounce address on reply-to-all), so it can be disabled
# here."""))
# )