Cannot save to sif file. (Synfig porting issue)
#### Steps to reproduce:
- Open Inkscape.
- Draw vector drawing.
- Click to File -> Save As...
- Save to ***.sif
#### What happened?
The message appeared:
Inkscape has received additional data from the script executed. The script did not return an error, but this may indicate the results will not be as expected.
```
Traceback (most recent call last):
File "synfig_output.py", line 1344, in <module>
e.affect(output=False)
File "inkex.py", line 283, in affect
self.effect()
File "synfig_output.py", line 1053, in effect
SynfigPrep.effect(self)
File "synfig_prepare.py", line 480, in effect
self.document = a.run_document()
File "synfig_prepare.py", line 153, in run_document
self.run_file(svgfile)
File "synfig_prepare.py", line 133, in run_file
p = Popen('inkscape "%s" %s' % (filename, cmd), shell=True, stdout=PIPE, stderr=PIPE)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xbe in position 19: ordinal not in range(128)
```
#### Inkscape Version and Operating System:
- Inkscape Version: 0.92.4
- Operating System: Windows 10
issue