better docker handling for shutdown

Dockerfile

@@ -40,7 +40,7 @@ RUN mkdir -p /app/emby-plugin && \
     echo '  echo "No Emby plugins directory found - skipping plugin deployment"' >> /app/deploy-plugin.sh && \
     echo '  echo "To enable plugin deployment, bind mount your Emby plugins directory to /emby-plugins"' >> /app/deploy-plugin.sh && \
     echo 'fi' >> /app/deploy-plugin.sh && \
-    echo 'exec python nfoguard.py' >> /app/deploy-plugin.sh && \
+    echo 'exec python -u nfoguard.py' >> /app/deploy-plugin.sh && \
     chmod +x /app/deploy-plugin.sh
 
 # Set ownership