Merge pull request #468 from Luzy2019/master

u-datetime-picker + input 模式下，弹窗后input框仍可以编辑

src/uni_modules/uview-plus/components/u-datetime-picker/u-datetime-picker.vue

@@ -2,6 +2,7 @@
     <view v-if="hasInput" class="u-datetime-picker">
         <u-input
             :placeholder="placeholder"
+			:readonly="!!showByClickInput"
             border="surround"
             v-model="inputValue"
             @click="showByClickInput = !showByClickInput"