Move Fail2Ban exceptions into central app.exceptions module

backend/app/routers/server.py

@@ -16,7 +16,7 @@ from app.dependencies import AuthDep, Fail2BanSocketDep
 from app.models.server import ServerSettingsResponse, ServerSettingsUpdate
 from app.services import server_service
 from app.exceptions import ServerOperationError
-from app.utils.fail2ban_client import Fail2BanConnectionError
+from app.exceptions import Fail2BanConnectionError
 
 router: APIRouter = APIRouter(prefix="/api/server", tags=["Server"])