fix a silly formatting error

Author: dietmarkuehl

tests/beman/execution26/exec-on.test.cpp

@@ -128,4 +128,4 @@ TEST(exec_on) {
     assert(on_id == pool_id);
     assert(cont_id == std::this_thread::get_id());
     assert(on_id != std::this_thread::get_id());
-}
+}