Use xeus::create_successful_reply routine in debugger modules request

Author: arjxn-py

src/xdebugger.cpp

@@ -404,11 +404,11 @@ namespace xpyt
             }
         }
 
-        return {
-            {"body", {
-                {"modules", mods},
-                {"totalModules", py::len(modules)}
-            }}
+        nl::json body = {
+            {"modules", mods},
+            {"totalModules", py::len(modules)}
         };
+
+        return xeus::create_successful_reply(nl::json::array(), body);
     }
 }