fix: #282隐藏宗旨字段

src/components/MyGroupItem.vue

@@ -16,7 +16,7 @@
             <b>行业:</b>
             <span>{{ data.industry }}</span>
           </p>
-          <p>
+          <p v-if="data.purpose">
             <b>宗旨:</b>
             <span>{{ data.purpose }}</span>
           </p>