fix(scw): read body with unknown content-length

[Codelax]

From go doc:

	// ContentLength records the length of the associated content. The
	// value -1 indicates that the length is unknown. Unless Request.Method
	// is "HEAD", values >= 0 indicate that the given number of bytes may
	// be read from Body.

Some requests may have -1 as content-length and still have a body that we must read. A long list response received chunked for example.