fix: convert smtp_port to int
fix: convert smtp_port to int

partly a regression from #857

DanielNeugebauer/adhocracy,alkadis/vcv,liqd/adhocracy,phihag/adhocracy,liqd/adhocracy,alkadis/vcv,phihag/adhocracy,phihag/adhocracy,phihag/adhocracy,alkadis/vcv,liqd/adhocracy,alkadis/vcv,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,alkadis/vcv,liqd/adhocracy,phihag/adhocracy