Applio allows arbitrary file removal in core.py

Applio is a voice conversion tool. Versions 3.2.8-bugfix and prior are vulnerable to arbitrary file removal in core.py. `output_tts_path` in tts.py takes arbitrary user input and passes it to `run_tts_script` function in core.py, which checks if the path in `output_tts_path` exists, and if yes, removes that path, which leads to arbitrary file removal. As of time of publication, no known patches are available.