Check for pipelines when setting page_gutter_class.

CHANGELOG

@@ -3,6 +3,7 @@ v 8.12.0 (unreleased)
   - Optimistic locking for Issues and Merge Requests (title and description overriding prevention)
 
 v 8.11.0 (unreleased)
+  - Fix pipelines tab layout regression (brycepj)
   - Use test coverage value from the latest successful pipeline in badge. !5862
   - Add test coverage report badge. !5708
   - Remove the http_parser.rb dependency by removing the tinder gem. !5758 (tbalthazar)

app/helpers/nav_helper.rb

@@ -25,6 +25,8 @@ module NavHelper
       current_path?('merge_requests#commits') ||
       current_path?('merge_requests#builds') ||
       current_path?('merge_requests#conflicts') ||
+      current_path?('merge_requests#pipelines') ||
+      
       current_path?('issues#show')
       if cookies[:collapsed_gutter] == 'true'
         "page-gutter right-sidebar-collapsed"