fix: skip if a symlink is broken

Signed-off-by: Dominik Willner <th33xitus@gmail.com>

kiauh/utils/fs_utils.py

@@ -211,6 +211,9 @@ def read_ports_from_nginx_configs() -> List[int]:
 
     port_list = []
     for config in NGINX_SITES_ENABLED.iterdir():
+        if not config.is_file():
+            continue
+
         with open(config, "r") as cfg:
             lines = cfg.readlines()