Default `authorized_keys_enabled` setting to true

What does this MR do?

Sets the column default for the Application Setting authorized_keys_enabled to true and rebuilds the authorized_keys file.

Why was this MR needed?

https://gitlab.com/gitlab-org/gitlab-ee/issues/2738

EE installations that were upgraded to 9.3 stopped writing to the authorized_keys file by default. The setting authorized_keys_enabled was nil. So additions and deletions of SSH keys had no effect on SSH operations.

When I added the setting, I mistakenly thought settings were merged with ApplicationSetting.defaults. However, if there exists an ApplicationSetting record, defaults is never used.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Fixes #2738 (closed)

app/assets/javascripts/environments/components/deploy_board_instance_component.vue

@@ -12,6 +12,7 @@
  * this information in the tooltip and the colors.
  * Mockup is https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1551#note_26595150
  */
+import tooltip from '../../vue_shared/directives/tooltip';
 
 export default {
   props: {
@@ -40,6 +41,10 @@ export default {
     },
   },
 
+  directives: {
+    tooltip,
+  },
+
   computed: {
     cssClass() {
       let cssClassName = `deploy-board-instance-${this.status}`;
@@ -55,10 +60,10 @@ export default {
 </script>
 <template>
   <div
-    class="deploy-board-instance has-tooltip"
+    v-tooltip
+    class="deploy-board-instance"
     :class="cssClass"
     :data-title="tooltipText"
-    data-toggle="tooltip"
     data-placement="top">
   </div>
 </template>