-make picky gcc happy

src/lib/exchange_api_withdraw.c

@@ -206,6 +206,7 @@ withdraw_cs_stage_two_callback (void *cls,
                                         wh);
     break;
   default:
+    {
       // the CSR request went wrong -> serve response to the callback
       struct TALER_EXCHANGE_WithdrawResponse wr = {
         .hr = csrr->hr
@@ -215,6 +216,7 @@ withdraw_cs_stage_two_callback (void *cls,
       TALER_EXCHANGE_withdraw_cancel (wh);
       break;
     }
+  }
 }