serve http: make it compile on go1.6 and go1.7

cmd/serve/http/http.go

@@ -9,7 +9,6 @@ import (
 	"path"
 	"strconv"
 	"strings"
-	"time"
 
 	"github.com/ncw/rclone/cmd"
 	"github.com/ncw/rclone/fs"
@@ -77,12 +76,11 @@ func (s *server) serve() {
 	mux.HandleFunc("/", s.handler)
 	// FIXME make a transport?
 	httpServer := &http.Server{
-		Addr:              s.bindAddress,
-		Handler:           mux,
-		ReadHeaderTimeout: 10 * time.Second, // time to send the headers
-		IdleTimeout:       60 * time.Second, // time to keep idle connections open
-		MaxHeaderBytes:    1 << 20,
+		Addr:           s.bindAddress,
+		Handler:        mux,
+		MaxHeaderBytes: 1 << 20,
 	}
+	initServer(httpServer)
 	fs.Logf(s.f, "Serving on http://%s/", bindAddress)
 	log.Fatal(httpServer.ListenAndServe())
 }

cmd/serve/http/http_new.go

@@ -0,0 +1,16 @@
+// HTTP parts go1.8+
+
+//+build go1.8
+
+package http
+
+import (
+	"net/http"
+	"time"
+)
+
+// Initialise the http.Server for pre go1.8
+func initServer(s *http.Server) {
+	s.ReadHeaderTimeout = 10 * time.Second // time to send the headers
+	s.IdleTimeout = 60 * time.Second       // time to keep idle connections open
+}

cmd/serve/http/http_old.go

@@ -0,0 +1,13 @@
+// HTTP parts pre go1.8
+
+//+build !go1.8
+
+package http
+
+import (
+	"net/http"
+)
+
+// Initialise the http.Server for pre go1.8
+func initServer(s *http.Server) {
+}