isolate url

My shell added the dot to the url and brought me to a non existing wikipedia page. Adding a space after the url prevents that from happening

pydantic_extra_types/currency_code.py

@@ -132,7 +132,7 @@ def _validate(cls, currency_symbol: str, _: core_schema.ValidationInfo) -> str:
             raise PydanticCustomError(
                 'InvalidCurrency',
                 'Invalid currency code.'
-                ' See https://en.wikipedia.org/wiki/ISO_4217. '
+                ' See https://en.wikipedia.org/wiki/ISO_4217 . '
                 'Bonds, testing and precious metals codes are not allowed.',
             )
         return currency_symbol