Update CHANGELOG for !4659

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CHANGELOG

@@ -69,7 +69,7 @@ v 8.9.0 (unreleased)
   - Measure queue duration between gitlab-workhorse and Rails
   - Added Gfm autocomplete for labels
   - Make Omniauth providers specs to not modify global configuration
-  - Remove unused JiraIssue class and replace references with ExternalIssue
+  - Remove unused JiraIssue class and replace references with ExternalIssue. !4659 (Ilan Shamir)
   - Make authentication service for Container Registry to be compatible with < Docker 1.11
   - Add Application Setting to configure Container Registry token expire delay (default 5min)
   - Cache assigned issue and merge request counts in sidebar nav