Fixed knex connection pool errors when saving posts with sqlite
Fixed knex connection pool errors when saving posts with sqlite

no issue

- sub query within the `Post.onSaving` method was not passing through the transaction options which was locking up sqlite

ErisDS/Ghost,ErisDS/Ghost,e10/Ghost,kevinansfield/Ghost,TryGhost/Ghost,janvt/Ghost,kevinansfield/Ghost,JohnONolan/Ghost,e10/Ghost,Kikobeats/Ghost,janvt/Ghost,TryGhost/Ghost,kevinansfield/Ghost,Kikobeats/Ghost,TryGhost/Ghost,bitjson/Ghost,JohnONolan/Ghost,bitjson/Ghost,JohnONolan/Ghost,ErisDS/Ghost,Kikobeats/Ghost