The odds opened about 10 days ago @1.90+ and after Grenland won the cup match against the same opponent the line went down. Personally I don't see anything strange here, regardelss of 85% procent of the money being on Grenland at BF.
Difficult to predict, it looks like Grenland is slightly better team, playing at home, but well scoring Valerenga is surely eager to make a revenge.
I would lean towards draw, but I just made BTTS @1.65, seems better bet to me.