nil/false should not be implicitly converted to integers in mrb_get_args(); close #1529

src/class.c

@@ -576,9 +576,6 @@ mrb_get_args(mrb_state *mrb, const char *format, ...)
                 *p = (mrb_int)f;
               }
               break;
-            case MRB_TT_FALSE:
-              *p = 0;
-              break;
             default:
               *p = mrb_fixnum(mrb_Integer(mrb, *sp));
               break;