修改openpopover的示例代码
修改openpopover的示例代码

避免因x值过大popover显示在屏幕外面，导致开发者认为此接口无效

pingping-jiang6141/appcan-docs-v2,xurigan/appcan-docs-v2,AppCanOpenSource/appcan-docs-v2,shangxianjing/appcan-docs-v2,shangxianjing/appcan-docs-v2,pingping-jiang6141/appcan-docs-v2,sandy1108/appcan-docs-v2,pingping-jiang6141/appcan-docs-v2,AppCanOpenSource/appcan-docs-v2,sandy1108/appcan-docs-v2,pingping-jiang6141/appcan-docs-v2,shangxianjing/appcan-docs-v2,sandy1108/appcan-docs-v2,shangxianjing/appcan-docs-v2,xurigan/appcan-docs-v2,AppCanOpenSource/appcan-docs-v2,AppCanOpenSource/appcan-docs-v2,sandy1108/appcan-docs-v2