Fix host being null, causing the list to not be displayed (#4718)

diff --git a/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/instance/pages/list/_source/list.vue b/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/instance/pages/list/_source/list.vue
index 69bd8ed..8b9d3b2 100644
--- a/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/instance/pages/list/_source/list.vue
+++ b/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/instance/pages/list/_source/list.vue
@@ -55,7 +55,7 @@
           <th scope="col" style="min-width: 135px">
             <span>{{$t('Executor')}}</span>
           </th>
-          <th scope="col" :style="{'min-width': ((Math.max(list.length && list[0].host.length, 22) + 40) * 6) + 'px'}">
+          <th scope="col" style="max-width: 600px">
             <span>{{$t('host')}}</span>
           </th>
           <th scope="col" style="min-width: 230px">
@@ -93,7 +93,7 @@
             <span v-if="item.executorName">{{item.executorName}}</span>
             <span v-else>-</span>
           </td>
-          <td><span>{{item.host || '-'}}</span></td>
+          <td style="max-width: 600px"><span style="padding-right: 5px">{{item.host || '-'}}</span></td>
           <td style="z-index: inherit;">
             <div v-show="item.disabled">
               <x-button type="info"
diff --git a/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/taskInstance/_source/list.vue b/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/taskInstance/_source/list.vue
index 6ee5409..d5b19d6 100644
--- a/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/taskInstance/_source/list.vue
+++ b/dolphinscheduler-ui/src/js/conf/home/pages/projects/pages/taskInstance/_source/list.vue
@@ -46,7 +46,7 @@
           <th scope="col" style="min-width: 130px">
             <span>{{$t('End Time')}}</span>
           </th>
-          <th scope="col" :style="{'min-width': (Math.max(list.length && list[0].host.length, 22) * 6) + 'px'}">
+          <th scope="col" style="max-width: 600px">
             <span>{{$t('host')}}</span>
           </th>
           <th scope="col" style="min-width: 70px">
@@ -87,7 +87,7 @@
             <span v-if="item.endTime">{{item.endTime | formatDate}}</span>
             <span v-else>-</span>
           </td>
-          <td><span>{{item.host || '-'}}</span></td>
+          <td style="max-width: 600px"><span style="padding-right: 5px">{{item.host || '-'}}</span></td>
           <td><span>{{item.duration}}</span></td>
           <td><span>{{item.retryTimes}}</span></td>
           <td>