Fixed scss_lint failure

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/10541

app/assets/stylesheets/framework/common.scss

@@ -403,8 +403,6 @@ img.emoji {
 .append-bottom-default { margin-bottom: $gl-padding; }
 .prepend-bottom-32 { margin-bottom: 32px; }
 .inline { display: inline-block; }
-.block { display: block; }
-.flex { display: flex; }
 .center { text-align: center; }
 .block { display: block; }
 .flex { display: flex; }

ee/app/assets/stylesheets/pages/environments.scss

-
 /**
  * Deploy boards
- */
- .deploy-board {
+*/
+.deploy-board {
   padding: 10px;
   background-color: $gray-light;
   min-height: 20px;