Fix CLI non-root developer mode

src/jlmkr/cli.py

@@ -31,7 +31,7 @@ from actions.stop import stop_jail
 
 def main():
     if os.stat(SCRIPT_PATH).st_uid != 0:
-      if os.environ.get('JLMKR_DEBUG') is not None:
+      if os.environ.get('JLMKR_DEBUG') is None:
         fail(
             f"This script should be owned by the root user... Fix it manually with: `chown root {SCRIPT_PATH}`."
         )