[py] Add character

Author: cgoldberg

py/selenium/webdriver/common/utils.py

@@ -49,7 +49,7 @@ def free_port() -> int:
         free_socket.listen(5)
         port: int = free_socket.getsockname()[1]
     except Exception as e:
-        raise RuntimeError(f"Can't find free port ({e})")
+        raise RuntimeError(f"Can't find free port: ({e})")
     finally:
         free_socket.close()
     return port