【报Bug】TabBarItem的visible会影响到midButton

示例代码：

pages.json

    "tabBar": {  
        "color": "#333333",  
        "selectedColor": "#286AFF",  
        "borderStyle": "#ebebeb",  
        "backgroundColor": "white",  
        "height": "50px",  
        "midButton": {  
            "backgroundImage": "/static/tabbar/mid-btn__icon1.gif",  
            "width": "55px",  
            "height": "55px"  
        },  
        "list": [  
            {  
                "pagePath": "pages/home/home",  
                "iconPath": "/static/tabbar/home.png",  
                "selectedIconPath": "/static/tabbar/home-selected.png",  
                "text": "首页",  
                "visible": false  
            },  
            {  
                "pagePath": "pages/water-rain/index",  
                "iconPath": "/static/tabbar/water-rain.png",  
                "selectedIconPath": "/static/tabbar/water-rain-selected.png",  
                "text": "服务",  
                "visible": false  
            },  
            {  
                "pagePath": "pages/workorder/index",  
                "iconPath": "/static/tabbar/workorder.png",  
                "selectedIconPath": "/static/tabbar/workorder-selected.png",  
                "text": "工单",  
                "visible": false  
            },  
            {  
                "pagePath": "pages/my/index",  
                "iconPath": "/static/tabbar/my.png",  
                "selectedIconPath": "/static/tabbar/my-selected.png",  
                "text": "我的"  
            }  
        ]  
    }

操作步骤：

调用以下代码后，midButton才显示

uni.setTabBarItem({  
            index: 2,  
            visible: true  
        })

预期结果：

控制tabarItem显示效果不影响midButton

实际结果：

控制tabarItem显示效果影响midButton