Seems like you can vote each month again, as I just got this E-Mail
Thank you for voting to add NodeBB to the Bitnami Library in our monthly contest. Unfortunately, they didn't receive enough votes to > > take the top spot last month.
Meet Last Month's Winner - MeteorJS
Still want to see NodeBB in the Bitnami Library? Each month is new chance to win! Vote for NodeBB again this month, and be sure to > > encourage your friends to vote too. You can vote for your favorite app each month until it wins.
The Bitnami Team
So, please vote for NodeBB here