[BUG] Pikcer组件

[MaerdDaed]

picker 组件中 params 传入参数 pickerParams: {year: true, month: false, day: false }时
1、同时配置startYear、endYear会导致选择列表为空

<u-picker startYear="1960" 
          endYear="2030" 
          v-model="historyShow" 
          :params="pickerParams" 
          mode="time">
</u-picker>

2、仅配置startYear时，defaultTime传入年份无效，若defaultTime手动拼接'-'号到年份末尾，则可正常显示
直接传入年份

<u-picker startYear="1960" 
          default-time="2002" 
          v-model="historyShow" 
          :params="pickerParams" 
          mode="time">
</u-picker>

手动拼接‘-’到年份末尾

<u-picker startYear="1960" 
          default-time="2002-" 
          v-model="historyShow" 
          :params="pickerParams" 
          mode="time">
</u-picker>

3、仅配置endYear时，选择列表为空

<u-picker endYear="1960" 
          v-model="historyShow" 
          :params="pickerParams" 
          mode="time">
</u-picker>

[ciscolxh]

这个组件文档好像不能限制 最大时间