Non-ASCII (Russian) text in image is not supported

[aleksejrs]

On GNU/Linux, when trying to generate cards with the string "тест" or any other Russian text:

Traceback (most recent call last):
File "/home/user/Anki/addons/image_occlusion_2/image_occlusion.py", line 130, in add_notes_non_overlapping
svg = etree.fromstring(svg_contents)
File "/home/user/Anki/addons/image_occlusion_2/etree/ElementTree.py", line 1301, in XML
parser.feed(text)
File "/home/user/Anki/addons/image_occlusion_2/etree/ElementTree.py", line 1641, in feed
self._parser.Parse(data, 0)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 186294-186297: ordinal not in range(128)