No, it's certainly not. If the bomb threat wasn't real (and I would definitely doubt that it was) that's a violation of the Convention on International Civil Aviation, Art. 5.
Even if it was real, odds are it would’ve been planted for exactly the same purpose.
Even if it was real, the distance from destination was nearly the same as from Minsk. There was no reason to divert the plane.
Lukashenko was trying his best to protect Europe from evil bomb. Can't blame him.
Good thing Belarus isn't a signatory to that convention and therefore it does not apply to them.