API should follow RequireSignInView (#8654) (#8661)

routers/api/v1/api.go

 		m.Group("/topics", func() {
 			m.Get("/search", repo.TopicSearch)
 		})
-	}, securityHeaders(), context.APIContexter(), sudo())
+	}, securityHeaders(), reqTokenBySetting(), context.APIContexter(), sudo())
 }
 
 func securityHeaders() macaron.Handler {
 		})
 	}
 }
+
+func reqTokenBySetting() macaron.Handler {
+	if setting.Service.RequireSignInView {
+		return reqToken()
+	}
+	return func(ctx *macaron.Context) {}
+}