LibGUI: Remove unnecessary type cast in JsonArrayModel.

Since TCP sequence numbers are randomly choosen 32-bit numbers, it often
happend that the most significant bit was set. The cast to a 32-bit
signed integer then made the number negative.

Thus TCP sequence were shown negative in the SystemMonitor every so
often.

Libraries/LibGUI/JsonArrayModel.cpp

@@ -107,7 +107,7 @@ Variant JsonArrayModel::data(const ModelIndex& index, ModelRole role) const
         if (field_spec.massage_for_display)
             return field_spec.massage_for_display(object);
         if (data.is_number())
-            return data.to_i32();
+            return data;
         return object.get(json_field_name).to_string();
     }