chore(DateTimePicker): adjust the existence conditions of t-date-time-picke__item--rroomly class

Author: anlyyao

src/date-time-picker/date-time-picker.wxml

@@ -21,7 +21,7 @@
   <t-picker-item
     wx:for="{{columns}}"
     wx:key="index"
-    class="{{_.cls(classPrefix + '__item', [['roomly', columns.length > 5 && index == 0]])}}"
+    class="{{_.cls(classPrefix + '__item', [['roomly', columns.length >= 5 && index == 0]])}}"
     options="{{item}}"
     index="index"
     format="{{formatter}}"