Merge pull request #1160 from Menrath/patch-2

Fix moodle coding style in example for delegated transactions

docs/apis/core/dml/index.md

@@ -636,7 +636,7 @@ try {
      // Assuming the both inserts work, we get to the following line.
      $transaction->allow_commit();
 
-} catch(Exception $e) {
+} catch (Exception $e) {
      $transaction->rollback($e);
 }
 ```