HTTP client caching plugin errors

[smakhtin]

When i do first request using httpCache plugin i receive error that the header name is wrong, then on every request i receive following errors:

"errors": [
		{
			"message": "Body has already been used. It can only be used once. Use tee() first if you need to read it twice.",
			"path": [
				"snis",
				0,
				"metadata"
			]
		},
		{
			"message": "Body has already been used. It can only be used once. Use tee() first if you need to read it twice.",
			"path": [
				"snis",
				1,
				"metadata"
			]
		}
	],

The response seems to come faster, so i assume some data is still cached.