Don't add review request button for a merged PR

Author: kemzeb

templates/repo/issue/view_content/sidebar.tmpl

@@ -91,7 +91,7 @@
 									{{svg "octicon-hourglass" 16}}
 								</span>
 							{{end}}
-							{{if .CanChange}}
+							{{if and .CanChange (not $.Issue.PullRequest.HasMerged)}}
 								<a href="#" class="ui muted icon re-request-review{{if .Checked}} checked{{end}}" data-tooltip-content="{{if .Checked}}{{ctx.Locale.Tr "repo.issues.remove_request_review"}}{{else}}{{ctx.Locale.Tr "repo.issues.re_request_review"}}{{end}}" data-issue-id="{{$.Issue.ID}}" data-id="{{.ItemID}}" data-update-url="{{$.RepoLink}}/issues/request_review">{{if .Checked}}{{svg "octicon-trash"}}{{else}}{{svg "octicon-sync"}}{{end}}</a>
 							{{end}}
 							{{svg (printf "octicon-%s" .Review.Type.Icon) 16 (printf "text %s" (.Review.HTMLTypeColorName))}}