Maintenance: unique choices from hardcoded servers

internal/constants/unique.go

@@ -0,0 +1,21 @@
+package constants
+
+import "sort"
+
+func makeUnique(slice []string) (uniques []string) {
+	set := make(map[string]struct{}, len(slice))
+	for _, element := range slice {
+		set[element] = struct{}{}
+	}
+
+	uniques = make([]string, 0, len(set))
+	for element := range set {
+		uniques = append(uniques, element)
+	}
+
+	sort.Slice(uniques, func(i, j int) bool {
+		return uniques[i] < uniques[j]
+	})
+
+	return uniques
+}