wikimg http cancel

wikimghttp.go

func (p *Puller) FirstColor(imgURL string) (xtermColor int, hex string, err error) {
	// Create a request so we can use req.Cancel
	req, err := http.NewRequest("GET", imgURL, nil)
	if err != nil {
		return
	}

	// Set up cancellation pipeline, link request to puller
	req.Cancel = p.Cancel
	
	// etc...
}