Fixes "a promise was created but was not returned" warning

[agdevbridge]

This would fix Warning: a promise was created in a handler but not returned from it
Issue: #1388

[kolpav]

Hope this will be merged soon

[elhigu]

I was thinking if just return would have been enough to keep previous functionality... but this seems harmless though so I'll just merge.

[aditbisa]

You forgot to put return in here: (line 49 & 52)

result.then((val) => {
          return transactor.commit(val)
        })
        .catch((err) => {
          return transactor.rollback(err)
        })