Fix default query params

[Deraen]

This allows RegexPatterns (e.g. silk/int) to be used inside silk/? without default-params.

If the default-params is not provided, silk/? will use new create-default method of Pattern to create the default.

(-create-default :foo) => {:foo nil}
(-create-default (silk/int :foo)) => (-create-default :foo) => {:foo nil}

[domkm]

Thanks!