Load livereload.js from "/"

Fix #1406
Instead of loading the file from http://localhost:port/, it can be
loaded from /.

transform/livereloadinject_test.go

@@ -0,0 +1,20 @@
+package transform
+
+import (
+	"bytes"
+	"github.com/spf13/hugo/helpers"
+	"testing"
+)
+
+func TestLiveReloadInject(t *testing.T) {
+	out := new(bytes.Buffer)
+	in := helpers.StringToReader("</body>")
+
+	tr := NewChain(LiveReloadInject)
+	tr.Apply(out, in, []byte("path"))
+
+	expected := `<script data-no-instant>document.write('<script src="/livereload.js?mindelay=10"></' + 'script>')</script></body>`
+	if string(out.Bytes()) != expected {
+		t.Errorf("Expected %s got %s", expected, string(out.Bytes()))
+	}
+}