BUG/MINOR: lua/filters: Return right code when txn:done() is called

txn functions can now be called from an action or a filter context. Thus the
return code must be adapted depending on this context. From an action, act.ABORT
is returned. From a filter, -1 is returned. It is the filter error code.

This bug only affects 2.5-dev. No backport needed.
1 file changed