fix MGs json

src/ringct/rctTypes.h

@@ -308,10 +308,10 @@ namespace rct {
             ar.tag("cc");
             FIELDS(MGs[i].cc)
             // MGs[i].II not saved, it can be reconstructed
+            ar.end_object();
+
             if (mg_elements - i > 1)
                ar.delimit_array();
-
-            ar.end_object();
           }
           ar.end_array();
           return true;