"leapp preupgrade" fails with "UnicodeEncodeError: 'charmap' codec can't encode character u'\uxxx' in position 1: character maps to <undefined>"

Issue

• When executing leapp preupgrade, the following backtrace is seen and leapp crashes

  Traceback (most recent call last):
    File "/usr/lib64/python2.7/multiprocessing/process.py", line 258, in _bootstrap
      self.run()
    File "/usr/lib64/python2.7/multiprocessing/process.py", line 114, in run
      self._target(*self._args, **self._kwargs)
    File "/usr/lib/python2.7/site-packages/leapp/repository/actor_definition.py", line 74, in _do_run
      actor_instance.run(*args, **kwargs)
    File "/usr/lib/python2.7/site-packages/leapp/actors/__init__.py", line 289, in run
      self.process(*args)
    File "/usr/share/leapp-repository/repositories/system_upgrade/common/actors/rootscanner/actor.py", line 19, in process
      self.produce(scan_dir(b'/'))
    File "/usr/share/leapp-repository/repositories/system_upgrade/common/actors/rootscanner/libraries/rootscanner.py", line 33, in scan_dir
      subdirs.append(_create_a_subdir(RootSubdirectory, subdir, os.path.join('/', subdir)))
    File "/usr/share/leapp-repository/repositories/system_upgrade/common/actors/rootscanner/libraries/rootscanner.py", line 16, in _create_a_subdir
      if os.path.islink(path):
    File "/usr/lib64/python2.7/posixpath.py", line 142, in islink
      st = os.lstat(path)
    File "/usr/lib64/python2.7/encodings/iso8859_15.py", line 12, in encode
      return codecs.charmap_encode(input,errors,encoding_table)
  UnicodeEncodeError: 'charmap' codec can't encode character u'\u2013' in position 1: character maps to <undefined>