Investigate python 2.7 rare issue

[Orsiris de Jong]

command_runner_init_.py:474: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
for line in iter(stream.readline, sentinel_char):

sentinel_char is compared to line we get from stdout/stderr stream.
Both should be unicode, since we use from __future__ import unicode_literals

Nevertheless, we don't get a equal comparaison.

[Orsiris de Jong]

Since we still get to end the queue reading even with that warning, we don't have much of a trouble. Still, it's bothering not to have an answer.