Update index.js

[fabdbt]

Minor refacto using id instead of re-fetching all.
Allow to not redefining session-id.

[victorsferreira]

Hey man, thanks for your time.
I believe it helps only in terms of readability because id uses the method get that invokes getAll
Was that your intention?

[fabdbt]

Yes that's it, only in terms of readability. Just wanted to refactor code using corresponding method that fetch id instead of re-making same code. May be easier if session-id needs to be changed.