make header match old 16px padding of body contents

app/assets/stylesheets/pages/merge_requests.scss

@@ -118,7 +118,7 @@
   .mr-widget-body,
   .ci_widget,
   .mr-widget-footer {
-    padding: 10px;
+    padding: 16px;
   }
 
   .mr-widget-pipeline-graph {
@@ -392,7 +392,7 @@
   border-color: $border-color;
   border-top-right-radius: 3px;
   border-top-left-radius: 3px;
-  padding: 10px;
+  padding: 16px;
   margin-bottom: -1px;
 }