controllers::helpers: Use json! macro to simplify JSON serialization code

Author: Turbo87

src/controllers/helpers.rs

@@ -5,10 +5,6 @@ pub(crate) mod pagination;
 pub(crate) use self::pagination::Paginate;
 
 pub fn ok_true() -> EndpointResult {
-    #[derive(Serialize)]
-    struct R {
-        ok: bool,
-    }
-
-    Ok(json_response(&R { ok: true }))
+    let json = json!({ "ok": true });
+    Ok(json_response(&json))
 }