message: Ignore vml in node or wx env
diff: @@ -6,11 +6,11 @@ var win = window;
  var vmlInited = false;
  -export var doc = win.document;
  +export var doc = win && win.document;
  export var createNode;
  -if (!env.canvasSupported) {
  +if (doc && !env.canvasSupported) {
  try {
  !doc.namespaces.zrvml && doc.namespaces.add('zrvml', urn);
  createNode = function (tagName) {
  @@ -26,7 +26,7 @@ if (!env.canvasSupported) {
  // From raphael
  export function initVML() {
  - if (vmlInited) {
  + if (vmlInited || !doc) {
  return;
  }
  vmlInited = true;
  