取消盖章方法

```javascript
MWF.xDesktop.requireApp("process.Xform", "Documenteditor", null, false);
MWF.APPDocumenteditor.implement({
cancelSeal: function(position){
var p = position || 0;
if (this.layout_seals && this.layout_seals.length){
if (this.layout_seals[p]){
this.layout_seals[p].hide();
this.layout_seals[p].src = "";
this.getSealData();
}
}
},
});
```