commit: fix exception handling on transaction close On SVN 1.6 at least, a failing pre-commit hook appears to abort a commit transaction without us needing to do it manually. This is apparently managed by a callback at the end of SVN's internal commit callback chain. Subsequently trying to abort an already-aborted transaction results in a spurious "Transaction cleanup failed" message that breaks tests. To fix this, we simply move the commit call out of try/except block.