Update providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/flags.py

Co-authored-by: Anton Grübel <anton.gruebel@gmail.com>
Signed-off-by: chrfwow <christian.lutnik@dynatrace.com>

Author: chrfwow

providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/flags.py

@@ -15,7 +15,7 @@ def _validate_metadata(key: str, value: typing.Union[float, int, str, bool]) ->
     elif not key:
         raise ParseError("key must not be empty")
     if value is None:
-        raise ParseError("Metadata value for key " + str(key) + " must be set")
+        raise ParseError(f"Metadata value for key {key} must be set")
     elif not isinstance(value, (float, int, str, bool)):
         raise ParseError(f"Metadata value {value} for key  {key} must be of type float, int, str or bool, but is {type(value)}")