Fix issue with setting user-data-dir in --uc mode

Author: mdmintz

seleniumbase/undetected/__init__.py

@@ -277,6 +277,7 @@ def __init__(
                 ):
                     config["profile"]["exit_type"] = None
                 fs.seek(0, 0)
+                fs.truncate()
                 json.dump(config, fs)
                 logger.debug("Fixed exit_type flag.")
         except Exception: