Upgrades to 2012.2~f1-0ubuntu1 fail due to syntax error in nova-common.postinst and error in config migrator

I previously had 2012.1-0ubuntu2.1.

Setting up nova-common (2012.2~f1-0ubuntu1) ...
Installing new version of config file /etc/nova/policy.json ...
Installing new version of config file /etc/nova/api-paste.ini ...
Installing new version of config file /etc/nova/nova.conf ...
/var/lib/dpkg/info/nova-common.postinst: 33: /var/lib/dpkg/info/nova-common.postinst: Syntax error: "fi" unexpected (expecting "then")
dpkg: error processing nova-common (--configure):
 subprocess installed post-installation script returned error exit status 2

This is because there is a typo at nova-common.postinst:26. When this is fixed (using the attached diff), it fails to convert my config file, also attached.

laney@raleigh> sudo dpkg --configure -a
Setting up nova-common (2012.2~f1-0ubuntu1) ...
Traceback (most recent call last):
  File "/usr/bin/nova-manage", line 1755, in <module>
    main()
  File "/usr/bin/nova-manage", line 1682, in main
    argv = FLAGS(sys.argv)
  File "/usr/lib/python2.7/dist-packages/nova/flags.py", line 45, in __call__
    return argv[:1] + super(NovaConfigOpts, self).__call__(argv[1:])
  File "/usr/lib/python2.7/dist-packages/nova/openstack/common/cfg.py", line 929, in __call__
    self._parse_config_files(from_file + from_dir)
  File "/usr/lib/python2.7/dist-packages/nova/openstack/common/cfg.py", line 1295, in _parse_config_files
    raise ConfigFileParseError(pe.filename, str(pe))
nova.openstack.common.cfg.ConfigFileParseError: Failed to parse /etc/nova/nova.conf: at /etc/nova/nova.conf:9, No ':' or '=' found in assignment: 'libvirt_use_virtio_for_bridges'
dpkg: error processing nova-common (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of nova-network:
 nova-network depends on nova-common (= 2012.2~f1-0ubuntu1); however:
  Package nova-common is not configured yet.
dpkg: error processing nova-network (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 nova-common
 nova-network