Fix 9.2. conflicts for "Fix locked milestone in boards being remove-able - 9.2 merge edition"

• Encountered conflicts while picking !1977 (merged) onto 9-2-stable-ee
• Please fix the conflicts and merge this into 9-2-stable-ee

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• https://gitlab.com/gitlab-org/gitlab-ee/blob/9339dec64edde53e562bbdc09678c38f2dfe3ccf/app/assets/javascripts/filtered_search/filtered_search_manager.js
• https://gitlab.com/gitlab-org/gitlab-ce/blob/b4972c4b237ad270ad1a4054c2fe2439d60ee06d/app/assets/javascripts/filtered_search/filtered_search_manager.js

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/cc @iamphill