Description of problem:
dnf fails with above error message when trying to install a group which is already installed

Version-Release number of selected component (if applicable):
Fedora 22

How reproducible:

Steps to Reproduce:
1. Installed Fedora22 vom Beta Libve DVD in German language
2. Updated system
3. dnf groupinstall LibreOffice => was successful
4. dnf groupinstall LibreOffice => failed with exception

Actual results:
[root@localhost ~]# dnf group install LibreOffice
Last metadata expiration check performed 0:45:51 ago on Tue May 26 10:47:03 2015.
Traceback (most recent call last):
  File "/bin/dnf", line 36, in <module>
    main.user_main(sys.argv[1:], exit_code=True)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 185, in user_main
    errcode = main(args)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 84, in main
    return _main(base, args)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 134, in _main
    cli.run()
  File "/usr/lib/python2.7/site-packages/dnf/cli/cli.py", line 1077, in run
    return self.command.run(self.base.extcmds)
  File "/usr/lib/python2.7/site-packages/dnf/cli/commands/group.py", line 385, in run
    return self.base.env_group_install(patterns, types)
  File "/usr/lib/python2.7/site-packages/dnf/base.py", line 1253, in env_group_install
    res.groups, types)
  File "/usr/lib/python2.7/site-packages/dnf/comps.py", line 88, in install_or_skip
    logger.warning("%s, %s", str(e)[:-1], _("skipping."))
UnicodeEncodeError: 'ascii' codec can't encode character u'\xbb' in position 7: ordinal not in range(128)


Expected results:
Some message like "Nothing to install"

Additional info: