series are being parse by unidiff python module and for some series [1], when converting a specific patch into a string, it raises the following exception:

Traceback (most recent call last):
  File "/usr/lib64/python2.7/unittest/case.py", line 329, in run
    testMethod()
  File "/home/lsandov1/repos/pt-oe/tests/patch/signed_off_by/test_signed_off_by.py", line 34, in test_signed_off_by_format
    payload = str(newpatch)
UnicodeEncodeError: 'ascii' codec can't encode character u'\u201c' in position 632: ordinal not in range(128)
None

[1] https://patchwork.openembedded.org/series/47/

This is another problem observed from the unidiff module (the other one is 
https://bugzilla.yoctoproject.org/show_bug.cgi?id=9953).