Python 3: remove a useless code to safe_encode()

The safe_encode method returns bytes, so we cannot concatenate its output with
text strings. This call does not seem needed after all, so let's just remove
it.

Change-Id: I6c18427559147d4c732ff7daa6d6006e7e5f6365
Merge "Python 3: remove a useless code to safe_encode()"