Replace absolute URLs on related branches/MRs with relative url to avoid hostname

Conflicts:
	app/views/projects/issues/show.html.haml

app/views/projects/issues/show.html.haml

@@ -87,10 +87,11 @@
               %h3.panel-title
                 Related issues
 
-    #merge-requests{ data: { url: referenced_merge_requests_project_issue_url(@project, @issue) } }
+
+    #merge-requests{ data: { url: referenced_merge_requests_project_issue_path(@project, @issue) } }
       // This element is filled in using JavaScript.
 
-    #related-branches{ data: { url: related_branches_project_issue_url(@project, @issue) } }
+    #related-branches{ data: { url: related_branches_project_issue_path(@project, @issue) } }
       // This element is filled in using JavaScript.
 
   .content-block.emoji-block

changelogs/unreleased/40555-replace-absolute-urls-with-related-branches-to-avoid-hostname.yml

+---
+title: Fix related branches/Merge requests failing to load when the hostname setting
+  is changed
+merge_request:
+author:
+type: fixed