Force uploader.py to unbuffered output to fix Docker logs timestamps

entrypoint.sh

@@ -87,7 +87,7 @@ case "$1" in
     rmdir "$STAGING_WARCS_DIR"
     ;;
   "uploader")
-    python ./uploader/uploader.py "$SHARED_WARCS_DIR/upload-queue/"
+    python -u ./uploader/uploader.py "$SHARED_WARCS_DIR/upload-queue/"
     ;;
   "analyzer")
     export UPDATES_CHANNEL=updates