Fix wrong closing tags in web UI HTML.

core/src/main/twirl/spark/deploy/master/executor_row.scala.html

@@ -3,7 +3,7 @@
 <tr>
   <td>@executor.id</td>
   <td>
-    <a href="@executor.worker.webUiAddress">@executor.worker.id</href>
+    <a href="@executor.worker.webUiAddress">@executor.worker.id</a>
   </td>
   <td>@executor.cores</td>
   <td>@executor.memory</td>

core/src/main/twirl/spark/deploy/master/worker_row.scala.html

@@ -4,7 +4,7 @@
 
 <tr>
   <td>
-    <a href="@worker.webUiAddress">@worker.id</href>
+    <a href="@worker.webUiAddress">@worker.id</a>
   </td>
   <td>@{worker.host}:@{worker.port}</td>
   <td>@worker.state</td>