[PrettyPrint] Slots Bug inside TripleExprs

[mistermboy]

Before PrettyPrint:

:Person  {
  schema:asd  {
    schema:asd  .  
  } or{ schema:sdaf .}
}

After PrettyPrint (wrong output):

:Person  {
  schema:asd  {
    schema:asd  . } schema:sdaf .  
  } or  {   
}