Fix styles in add issues to issue board modal

app/assets/javascripts/boards/components/modal/list.js

@@ -133,9 +133,9 @@ gl.issueBoards.ModalList = Vue.extend({
         <div
           v-for="issue in group"
           v-if="showIssue(issue)"
-          class="card-parent">
+          class="board-card-parent">
           <div
-            class="card"
+            class="board-card"
             :class="{ 'is-active': issue.selected }"
             @click="toggleIssue($event, issue)">
             <issue-card-inner