Formatting fix

Author: jholveck

src/mss/base.py

@@ -185,7 +185,8 @@ def __init__(
             if kwarg_name in kwargs and os_ != target_platform:
                 kwargs.pop(kwarg_name)
                 warnings.warn(
-                    f"{kwarg_name} is only used on {target_platform} and ignored on other platforms. This will be an error in the future.",
+                    f"{kwarg_name} is only used on {target_platform} and ignored on other platforms. "
+                    "This will be an error in the future.",
                     DeprecationWarning,
                     stacklevel=2,
                 )