Stay consistent with date question message

app/helpers/merge_requests_helper.rb

@@ -15,6 +15,7 @@ module MergeRequestsHelper
       "existing_absorbing_organisation" => "Answer if absorbing organisation is already active",
       "helpdesk_ticket" => "Enter helpdesk ticket number",
       "merging_organisations" => "Add merging organisations",
+      "merge_date" => "Set merge date",
     }
     messages[page] || "Enter #{lowercase_first_letter(page.humanize)}"
   end