fix: /ip should not include port number (#212)

Author: mccutchen

httpbin/helpers.go

@@ -12,6 +12,7 @@ import (
 	"math/rand"
 	"mime"
 	"mime/multipart"
+	"net"
 	"net/http"
 	"net/url"
 	"regexp"
@@ -64,7 +65,12 @@ func getClientIP(r *http.Request) string {
 	}
 
 	// Finally, fall back on the actual remote addr from the request.
-	return r.RemoteAddr
+	remoteAddr := r.RemoteAddr
+	if strings.IndexByte(remoteAddr, ':') > 0 {
+		ip, _, _ := net.SplitHostPort(remoteAddr)
+		return ip
+	}
+	return remoteAddr
 }
 
 func getURL(r *http.Request) *url.URL {