chore(docker): run with debug output

Dockerfile

@@ -7,4 +7,4 @@ COPY . .
 
 RUN pip install -r requirements.txt
 
-CMD ["python", "-OO", "main.py"]
+CMD ["python", "main.py"]

audio/youtubedl.py

@@ -46,6 +46,8 @@ class YTDLSource(PCMVolumeTransformer):
             if not data["entries"]:
                 raise Exception("no results found!")
             data = data["entries"][0]
+            if "url" not in data:
+                raise Exception("no url returned!")
 
         return cls(
             TrackedAudioSource(