fix windows case

radicale/utils.py

@@ -18,7 +18,6 @@
 # along with Radicale.  If not, see <http://www.gnu.org/licenses/>.
 
 import getpass
-import grp
 import os
 import pwd
 import ssl
@@ -29,6 +28,9 @@ from typing import Callable, Sequence, Tuple, Type, TypeVar, Union
 from radicale import config
 from radicale.log import logger
 
+if sys.platform != "win32":
+    import grp
+
 _T_co = TypeVar("_T_co", covariant=True)
 
 RADICALE_MODULES: Sequence[str] = ("radicale", "vobject", "passlib", "defusedxml",