[`torrent`] Create `download_dir` if it doesn't exist.

platypush/plugins/torrent/__init__.py

@@ -1,4 +1,5 @@
 import os
+import pathlib
 import queue
 import random
 import threading
@@ -67,6 +68,8 @@ class TorrentPlugin(Plugin):
             'tv': f'{popcorn_base_url}/show/{{}}',
         }
 
+        pathlib.Path(self.download_dir).mkdir(parents=True, exist_ok=True)
+
     @action
     def search(
         self,