Remove restriction on EVCPID

https://dev.wormwood.com.sg/zentao/task-view-236.html

Strides-Admin/src/views/charge/AddStation.vue

@@ -416,7 +416,7 @@
             message: 'Please type charge station id'
           },
           "evcpId": {
-            required: true,
+            required: false,
             trigger: 'blur',
             message: 'Please type EVCPID'
           },