fix http: request body too large err

[dogancanbakir]

Closes #377

test:

func TestResponseChain_Fill(t *testing.T) {
	resp, err := http.Get("https://download.binance.com/electron-desktop/mac/production/binance.dmg")
	require.Nil(t, err)
	require.NotNil(t, resp)

	rc := NewResponseChain(resp, int64(4<<20))
	err = rc.Fill()
	require.Nil(t, err)

	headers := rc.Headers().String()
	body := rc.Body().String()
	fullResponse := rc.FullResponse().String()

	require.Contains(t, headers, "application/x-apple-diskimage")
	require.Contains(t, fullResponse, headers)
	require.NotEmpty(t, body)
}

[Mzack9999]

lgtm - In general, within nuclei, I think that we should probably push into the direction to set a large maximum body size to avoid infinite reading, and at the same time opt for cold storage buffer for large bodies (ex disk backed bytes.Buffer)